.. _dpiStmtFunctions:
ODPI-C Statement Functions
--------------------------
Statement handles are used to represent statements of all types (queries, DML,
DDL and PL/SQL). They are created by calling the function
:func:`dpiConn_prepareStmt()` or the function :func:`dpiSubscr_prepareStmt()`.
They are also created implicitly when a variable of type DPI_ORACLE_TYPE_STMT
is created. Statement handles can be closed by calling the function
:func:`dpiStmt_close()` or by releasing the last reference to the statement by
calling the function :func:`dpiStmt_release()`.
.. function:: int dpiStmt_addRef(dpiStmt* stmt)
Adds a reference to the statement. This is intended for situations where a
reference to the statement needs to be maintained independently of the
reference returned when the statement was created.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- The statement to which a reference is to be added. If the reference
is NULL or invalid, an error is returned.
.. function:: int dpiStmt_bindByName(dpiStmt* stmt, const char* name, \
uint32_t nameLength, dpiVar* var)
Binds a variable to a named placeholder in the statement. A reference to
the variable is retained by the library and is released when the statement
itself is released or a new variable is bound to the same name.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to have the variable bound.
If the reference is NULL or invalid, an error is returned.
* - ``name``
- IN
- A byte string in the encoding used for CHAR data giving the name
of the placeholder which is to be bound.
* - ``nameLength``
- IN
- The length of the name parameter, in bytes.
* - ``var``
- IN
- A reference to the variable which is to be bound. If the reference
is NULL or invalid, an error is returned.
.. function:: int dpiStmt_bindByPos(dpiStmt* stmt, uint32_t pos, dpiVar* var)
Binds a variable to a placeholder in the statement by position. A reference
to the variable is retained by the library and is released when the
statement itself is released or a new variable is bound to the same
position.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to have the variable bound.
If the reference is NULL or invalid, an error is returned.
* - ``pos``
- IN
- The position which is to be bound. The position of a placeholder
is determined by its location in the statement. Placeholders are
numbered from left to right, starting from 1, and duplicate names
do not count as additional placeholders.
* - ``var``
- IN
- A reference to the variable which is to be bound. If the reference
is NULL or invalid, an error is returned.
.. function:: int dpiStmt_bindValueByName(dpiStmt* stmt, const char* name, \
uint32_t nameLength, dpiNativeTypeNum nativeTypeNum, dpiData* data)
Binds a value to a named placeholder in the statement without the need to
create a variable directly. One is created implicitly and released when the
statement is released or a new value is bound to the same name.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to have the variable bound.
If the reference is NULL or invalid, an error is returned.
* - ``name``
- IN
- A byte string in the encoding used for CHAR data giving the name
of the placeholder which is to be bound.
* - ``nameLength``
- IN
- The length of the name parameter, in bytes.
* - ``nativeTypeNum``
- IN
- The type of data that is being bound. It is expected to be one of
the values from the enumeration
:ref:`dpiNativeTypeNum<dpiNativeTypeNum>`.
* - ``data``
- IN
- The data which is to be bound, as a pointer to a
:ref:`dpiData<dpiData>` structure. A variable will be created
based on the type of data being bound and a reference to this
variable retained. Once the statement has been executed, this new
variable will be released.
.. function:: int dpiStmt_bindValueByPos(dpiStmt* stmt, uint32_t pos, \
dpiNativeTypeNum nativeTypeNum, dpiData* data)
Binds a value to a placeholder in the statement without the need to create
a variable directly. One is created implicitly and released when the
statement is released or a new value is bound to the same position.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to have the variable bound.
If the reference is NULL or invalid, an error is returned.
* - ``pos``
- IN
- The position which is to be bound. The position of a placeholder
is determined by its location in the statement. Placeholders are
numbered from left to right, starting from 1, and duplicate names
do not count as additional placeholders.
* - ``nativeTypeNum``
- IN
- The type of data that is being bound. It is expected to be one of
the values from the enumeration
:ref:`dpiNativeTypeNum<dpiNativeTypeNum>`.
* - ``data``
- IN
- The data which is to be bound, as a pointer to a
:ref:`dpiData<dpiData>` structure. A variable will be created
based on the type of data being bound and a reference to this
variable retained. Once the statement has been executed, this
new variable will be released.
.. function:: int dpiStmt_close(dpiStmt* stmt, const char* tag, \
uint32_t tagLength)
Closes the statement and makes it unusable for further work immediately,
rather than when the reference count reaches zero.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to be closed. If the
reference is NULL or invalid, an error is returned.
* - ``tag``
- IN
- A key to associate the statement with in the statement cache, in
the encoding used for CHAR data. NULL is also acceptable in which
case the statement is not tagged. This value is ignored for
statements that are acquired through bind variables (REF CURSOR)
or implicit results.
* - ``tagLength``
- IN
- The length of the tag parameter, in bytes, or 0 if the tag
parameter is NULL.
.. function:: int dpiStmt_define(dpiStmt* stmt, uint32_t pos, dpiVar* var)
Defines the variable that will be used to fetch rows from the statement. A
reference to the variable will be retained until the next define is
performed on the same position or the statement is closed.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement on which the variable is to be
defined. If the reference is NULL or invalid, an error is
returned. Note that the statement must have already been executed
or an error is returned.
* - ``pos``
- IN
- The position which is to be defined. The first position is 1.
* - ``var``
- IN
- A reference to the variable which is to be used for fetching rows
from the statement at the given position. If the reference is NULL
or invalid, an error is returned.
.. function:: int dpiStmt_defineValue(dpiStmt* stmt, uint32_t pos, \
dpiOracleTypeNum oracleTypeNum, dpiNativeTypeNum nativeTypeNum, \
uint32_t size, int sizeIsBytes, dpiObjectType* objType)
Defines the type of data that will be used to fetch rows from the
statement. This is intended for use with the function
:func:`dpiStmt_getQueryValue()`, when the default data type derived from
the column metadata needs to be overridden by the application. Internally,
a variable is created with the specified data type and size.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement on which the define is to take place.
If the reference is NULL or invalid, an error is returned. Note
that the statement must have already been executed or an error is
returned.
* - ``pos``
- IN
- The position which is to be defined. The first position is 1.
* - ``oracleTypeNum``
- IN
- The type of Oracle data that is to be used. It should be one of
the values from the enumeration
:ref:`dpiOracleTypeNum<dpiOracleTypeNum>`.
* - ``nativeTypeNum``
- IN
- The type of native C data that is to be used. It should be one of
the values from the enumeration
:ref:`dpiNativeTypeNum<dpiNativeTypeNum>`.
* - ``size``
- IN
- The maximum size of the buffer used for transferring data to/from
Oracle. This value is only used for variables transferred as byte
strings. Size is either in characters or bytes depending on the
value of the sizeIsBytes parameter. If the value is in characters,
internally the value will be multipled by the maximum number of
bytes for each character and that value used instead when
determining the necessary buffer size.
* - ``sizeIsBytes``
- IN
- A boolean value indicating if the size parameter refers to
characters or bytes. This flag is only used if the variable refers
to character data.
* - ``objType``
- IN
- A reference to the object type of the object that is being bound
or fetched. This value is only used if the Oracle type is
DPI_ORACLE_TYPE_OBJECT.
.. function:: int dpiStmt_deleteFromCache(dpiStmt* stmt)
Excludes the associated SQL statement from the statement cache. If the
SQL statement was not already in the cache, it will not be added. This
function can be called before or after the statment is executed.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to be excluded from the
statement cache. If the reference is NULL or invalid, an error is
returned.
.. function:: int dpiStmt_execute(dpiStmt* stmt, dpiExecMode mode, \
uint32_t* numQueryColumns)
Executes the statement using the bound values. For queries this makes
available metadata which can be acquired using the function
:func:`dpiStmt_getQueryInfo()`. For non-queries, out and in-out variables
are populated with their values.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to be executed. If the
reference is NULL or invalid, an error is returned.
* - ``mode``
- IN
- One or more of the values from the enumeration
:ref:`dpiExecMode<dpiExecMode>`, OR'ed together.
* - ``numQueryColumns``
- OUT
- A pointer to the number of columns which are being queried, which
will be populated upon successful execution of the statement. If
the statement does not refer to a query, the value is set to 0.
This parameter may also be NULL.
.. function:: int dpiStmt_executeMany(dpiStmt* stmt, dpiExecMode mode, \
uint32_t numIters)
Executes the statement the specified number of times using the bound
values. Each bound variable must have at least this many elements allocated
or an error is returned.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to be executed. If the
reference is NULL or invalid, an error is returned.
* - ``mode``
- IN
- One or more of the values from the enumeration
:ref:`dpiExecMode<dpiExecMode>`, OR'ed together. Note that modes
DPI_MODE_EXEC_BATCH_ERRORS and DPI_MODE_EXEC_ARRAY_DML_ROWCOUNTS
are only supported with insert, update, delete and merge
statements.
* - ``numIters``
- IN
- The number of times the statement is executed. Each iteration
corresponds to one of the elements of the array that was bound
earlier.
.. function:: int dpiStmt_fetch(dpiStmt* stmt, int* found, \
uint32_t* bufferRowIndex)
Fetches a single row from the buffers defined for the query. If no row is
available in the buffers, an internal fetch takes place to populate them,
if rows are available. The number of rows fetched into the internal
buffers can be set by calling :func:`dpiStmt_setFetchArraySize()`. If the
statement does not refer to a query an error is returned. All columns that
have not been defined prior to this call are implicitly defined using the
metadata made available when the statement was executed.
The function :func:`dpiStmt_fetchRows()` should be used instead of this
function if it is important to control when the internal fetch (and
round-trip to the database) takes place.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which a row is to be fetched. If
the reference is NULL or invalid, an error is returned.
* - ``found``
- OUT
- A pointer to a boolean value indicating if a row was fetched or
not, which will be populated upon successful completion of this
function.
* - ``bufferRowIndex``
- OUT
- A pointer to the buffer row index which will be populated upon
successful completion of this function if a row is found. This
index is used as the array position for getting values from the
variables that have been defined for the statement.
.. function:: int dpiStmt_fetchRows(dpiStmt* stmt, uint32_t maxRows, \
uint32_t* bufferRowIndex, uint32_t* numRowsFetched, int* moreRows)
Returns the number of rows that are available in the buffers defined for
the query. If no rows are currently available in the buffers, an internal
fetch takes place in order to populate them, if rows are available. The
number of rows fetched into the internal buffers can be set by calling
:func:`dpiStmt_setFetchArraySize()`. If the statement does not refer to a
query an error is returned. All columns that have not been defined prior to
this call are implicitly defined using the metadata made available when the
statement was executed.
This function should be used instead of :func:`dpiStmt_fetch()` if it is
important to control when the internal fetch (and round-trip to the
database) takes place.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which rows are to be fetched. If
the reference is NULL or invalid, an error is returned.
* - ``maxRows``
- IN
- The maximum number of rows to fetch. If the number of rows
available exceeds this value only this number will be fetched.
* - ``bufferRowIndex``
- OUT
- A pointer to the buffer row index which will be populated upon
successful completion of this function. This index is used as the
array position for getting values from the variables that have
been defined for the statement.
* - ``numRowsFetched``
- OUT
- A pointer to the number of rows that have been fetched, populated
after the call has completed successfully.
* - ``moreRows``
- OUT
- A pointer to a boolean value indicating if there are potentially
more rows that can be fetched after the ones fetched by this
function call.
.. function:: int dpiStmt_getBatchErrorCount(dpiStmt* stmt, uint32_t* count)
Returns the number of batch errors that took place during the last
execution with batch mode enabled. Batch errors are only available when
both the client and the server are at 12.1.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the number of batch errors
is to be retrieved. If the reference is NULL or invalid, an error
is returned.
* - ``count``
- OUT
- A pointer to the number of batch errors that took place, which is
populated after successful completion of the function.
.. function:: int dpiStmt_getBatchErrors(dpiStmt* stmt, uint32_t numErrors, \
dpiErrorInfo* errors)
Returns the batch errors that took place during the last execution with
batch mode enabled. Batch errors are only available when both the client
and the server are at 12.1.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the batch errors are to be
retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``numErrors``
- IN
- The size of the errors array in number of elements. The number of
batch errors that are available can be determined using
:func:`dpiStmt_getBatchErrorCount()`.
* - ``errors``
- IN
- A pointer to the first element of an array of
:ref:`dpiErrorInfo<dpiErrorInfo>` structures which is assumed to
contain the number of elements specified by the numErrors
parameter.
.. function:: int dpiStmt_getBindCount(dpiStmt* stmt, uint32_t* count)
Returns the number of bind variables in the prepared statement. In SQL
statements this is the total number of bind variables whereas in PL/SQL
statements this is the count of the **unique** bind variables.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the number of bind
variables is to be retrieved. If the reference is NULL or invalid,
an error is returned.
* - ``count``
- OUT
- A pointer to the number of bind variables found in the statement,
which is populated upon successful completion of the function.
.. function:: int dpiStmt_getBindNames(dpiStmt* stmt, uint32_t* numBindNames, \
const char** bindNames, uint32_t* bindNameLengths)
Returns the names of the unique bind variables in the prepared statement.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the names of bind variables
are to be retrieved. If the reference is NULL or invalid, an error
is returned.
* - ``numBindNames``
- IN/OUT
- A pointer to the size of the bindNames and bindNameLengths arrays
in number of elements. This value must be large enough to hold all
of the unique bind variables in the prepared statement or an error
will be returned. The maximum number of bind variables can be
determined by calling :func:`dpiStmt_getBindCount()`. Upon
successful completion of this function, the actual number of
unique bind variables in the prepared statement will be populated.
* - ``bindNames``
- OUT
- An array of pointers to byte strings in the encoding used for CHAR
data. The size of the array is specified using the numBindNames
parameter. When the function completes this array will be filled
with the names of the unique bind variables in the statement.
* - ``bindNameLengths``
- OUT
- A pointer to the first element of an array of integers containing
the lengths of the bind variable names which is filled in upon
successful completion of the function. The number of elements is
assumed to be specified by the numBindNames parameter.
.. function:: int dpiStmt_getFetchArraySize(dpiStmt* stmt, uint32_t* arraySize)
Gets the array size used for performing fetches.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the fetch array size is to
be retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``arraySize``
- OUT
- A pointer to the value which will be populated upon successful
completion of this function.
.. function:: int dpiStmt_getImplicitResult(dpiStmt* stmt, \
dpiStmt** implicitResult)
Returns the next implicit result available from the last execution of the
statement. Implicit results are only available when both the client and
server are 12.1 or higher.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the next implicit result
is to be retrieved. If the reference is NULL or invalid, an error
is returned.
* - ``implicitResult``
- OUT
- A pointer to a reference to a statement which will be populated
with the next implicit result upon successful completion of the
function. If no implicit results remain, the reference will be set
to NULL. The reference that is returned must be released as soon
as it is no longer needed.
.. function:: int dpiStmt_getInfo(dpiStmt* stmt, dpiStmtInfo* info)
Returns information about the statement.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which information is to be
retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``info``
- OUT
- A pointer to a structure of type :ref:`dpiStmtInfo<dpiStmtInfo>`
which will be filled in with information about the statement upon
successful completion of the function.
.. function:: int dpiStmt_getLastRowid(dpiStmt* stmt, dpiRowid** rowid)
Returns the rowid of the last row that was affected by the statement.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the rowid of the last row
affected is to be retrieved. If the reference is NULL or invalid,
an error is returned.
* - ``rowid``
- OUT
- A pointer to a rowid which will be populated upon successful
completion of this function. If no statement has been executed,
the last statement executed was not a DML statement or no rows
were affected by a DML statement, the value returned will be NULL.
If a rowid is returned, the reference will remain valid until the
next call to this function or until the statement is closed. If
the reference is needed for a longer period of time, call
:func:`dpiRowid_addRef()` to acquire an independent reference (and
call :func:`dpiRowid_release()` when that reference is no longer
required).
.. function:: int dpiStmt_getNumQueryColumns(dpiStmt* stmt, \
uint32_t* numQueryColumns)
Returns the number of columns that are being queried.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the number of query columns
is to be retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``numQueryColumns``
- OUT
- A pointer to the number of columns which are being queried by the
statement, which is filled in upon successful completion of the
function. If the statement does not refer to a query, the value is
populated with 0.
.. function:: int dpiStmt_getOciAttr(dpiStmt* stmt, uint32_t attribute, \
dpiDataBuffer* value, uint32_t* valueLength)
Returns the value of an OCI attribute. This is intended solely for testing
attributes that are not otherwise supported by ODPI-C and should not be
used for any other purpose. Use only as directed by Oracle.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the OCI attribute is to be
returned. If the reference is NULL or invalid, an error is
returned.
* - ``attribute``
- IN
- The attribute to acquire.
* - ``value``
- OUT
- A data buffer which will be populated with the value of the OCI
attribute upon successfully completing this function.
* - ``valueLength``
- OUT
- The length of the attribute which will be populated upon
succesfully completing this function.
.. function:: int dpiStmt_getPrefetchRows(dpiStmt* stmt, uint32_t* numRows)
Gets the number of rows that will be prefetched by the Oracle Client
library when a query is executed.
The value may be changed by calling :func:`dpiStmt_setPrefetchRows()`.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the number of rows to
prefetch is to be retrieved. If the reference is NULL or invalid,
an error is returned.
* - ``numRows``
- OUT
- A pointer to the value which will be populated upon successful
completion of this function.
.. function:: int dpiStmt_getQueryInfo(dpiStmt* stmt, uint32_t pos, \
dpiQueryInfo* info)
Returns information about the column that is being queried.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the column metadata is to
be retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``pos``
- IN
- The position of the column whose metadata is to be retrieved. The
first position is 1.
* - ``info``
- OUT
- A pointer to a :ref:`dpiQueryInfo<dpiQueryInfo>` structure which
will be filled in upon successful completion of the function.
.. function:: int dpiStmt_getQueryValue(dpiStmt* stmt, uint32_t pos, \
dpiNativeTypeNum* nativeTypeNum, dpiData** data)
Returns the value of the column at the given position for the currently
fetched row, without needing to provide a variable. If the data type of
the column needs to be overridden, the function
:func:`dpiStmt_defineValue()` can be called to specify a different type
after executing the statement but before fetching any data.
This function should only be called after a call to the function
:func:`dpiStmt_fetch()` has succeeded and indicated that a row is
available.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the column value is to be
retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``pos``
- IN
- The position of the column whose value is to be retrieved. The
first position is 1.
* - ``nativeTypeNum``
- OUT
- A pointer to the native type that is used by the value, which will
be populated upon successful completion of this function. It will
be one of the values from the enumeration
:ref:`dpiNativeTypeNum<dpiNativeTypeNum>`.
* - ``data``
- OUT
- A pointer to a reference to an internally created
:ref:`dpiData<dpiData>` structure which will be populated upon
successful completion of this function. The structure contains the
value of the column at the specified position. Note that any
references to LOBs, statements, objects, and rowids are owned by
the statement. If you wish to retain these values independently of
the statement, a reference must be added by calling one of
:func:`dpiLob_addRef()`, :func:`dpiStmt_addRef()`,
:func:`dpiObject_addRef()` or :func:`dpiRowid_addRef()`.
.. function:: int dpiStmt_getRowCount(dpiStmt* stmt, uint64_t* count)
Returns the number of rows affected by the last DML statement that was
executed, the number of rows currently fetched from a query, or the number
of successful executions of a PL/SQL block. In all other cases 0 is
returned.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the row count is to be
retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``count``
- OUT
- A pointer to the row count which will be populated upon successful
completion of the function.
.. function:: int dpiStmt_getRowCounts(dpiStmt* stmt, \
uint32_t* numRowCounts, uint64_t** rowCounts)
Returns an array of row counts affected by the last invocation of
:func:`dpiStmt_executeMany()` with the array DML rowcounts mode enabled.
This feature is only available if both client and server are at 12.1.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the row counts are to be
retrieved. If the reference is NULL or invalid, an error is
returned.
* - ``numRowCounts``
- OUT
- A pointer to the size of the rowCounts array which is being
returned. It is populated upon successful completion of the
function.
* - ``rowCounts``
- OUT
- A pointer to an array of row counts which is populated upon
successful completion of the function. This array should be
considered read-only.
.. function:: int dpiStmt_getSubscrQueryId(dpiStmt* stmt, uint64_t* queryId)
Returns the id of the query that was just registered on the subscription
by calling :func:`dpiStmt_execute()` on a statement prepared by calling
:func:`dpiSubscr_prepareStmt()`.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement from which the query id should be
retrieved. This statement should have been prepared using the
function :func:`dpiSubscr_prepareStmt()`. If the reference is NULL
or invalid an error is returned.
* - ``queryId``
- OUT
- A pointer to the query id, which is filled in upon successful
completion of the function.
.. function:: int dpiStmt_release(dpiStmt* stmt)
Releases a reference to the statement. A count of the references to the
statement is maintained and when this count reaches zero, the memory
associated with the statement is freed and the statement is closed if that
has not already taken place using the function :func:`dpiStmt_close()`.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- The statement from which a reference is to be released. If the
reference is NULL or invalid, an error is returned.
.. function:: int dpiStmt_scroll(dpiStmt* stmt, dpiFetchMode mode, \
int32_t offset, int32_t rowCountOffset)
Scrolls the statement to the position in the cursor specified by the mode
and offset.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement which is to be scrolled to a
particular row position. If the reference is NULL or invalid, an
error is returned.
* - ``mode``
- IN
- One of the values from the enumeration
:ref:`dpiFetchMode<dpiFetchMode>`.
* - ``offset``
- IN
- A value which is used with the mode in order to determine the row
position in the cursor.
* - ``rowCountOffset``
- IN
- An offset to the row count used when calculating the desired row
to be fetched. This is needed when a client has fetched multiple
rows but has not yet consumed all of them. If this is not being
done by the client, the value 0 is appropriate.
.. function:: int dpiStmt_setFetchArraySize(dpiStmt* stmt, uint32_t arraySize)
Sets the array size used for performing fetches. All variables defined for
fetching must have this many (or more) elements allocated for them. The
higher this value is the less network round trips are required to fetch
rows from the database but more memory is also required. A value of zero
will reset the array size to the default value of
DPI_DEFAULT_FETCH_ARRAY_SIZE.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement on which the fetch array size is to
be set. If the reference is NULL or invalid, an error is returned.
* - ``arraySize``
- IN
- The number of rows which should be fetched each time more rows
need to be fetched from the database.
.. function:: int dpiStmt_setOciAttr(dpiStmt* stmt, uint32_t attribute, \
void* value, uint32_t valueLength)
Sets the value of an OCI attribute. This is intended solely for testing
attributes that are not otherwise supported by ODPI-C and should not be
used for any other purpose. Use only as directed by Oracle.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement on which the OCI attribute is to be
set. If the reference is NULL or invalid, an error is returned.
* - ``attribute``
- IN
- The attribute to set.
* - ``value``
- IN
- A pointer to the data which is to be set.
* - ``valueLength``
- IN
- The length of the data which is to be set.
.. function:: int dpiStmt_setPrefetchRows(dpiStmt* stmt, uint32_t numRows)
Sets the number of rows that will be prefetched by the Oracle Client
library when a query is executed. The default value is
`DPI_DEFAULT_PREFETCH_ROWS` (2). Increasing this value may reduce the
number of round-trips to the database that are required in order to
fetch rows, but at the cost of increasing memory requirements. Setting this
value to 0 will disable prefetch completely, which may be useful when
the timing for fetching rows must be controlled by the caller.
The current value can be determined by calling
:func:`dpiStmt_getPrefetchRows()`.
The function returns DPI_SUCCESS for success and DPI_FAILURE for failure.
.. parameters-table::
* - ``stmt``
- IN
- A reference to the statement on which the number of rows to
prefetch is to be set. If the reference is NULL or invalid, an
error is returned.
* - ``numRows``
- OUT
- The number of rows to prefetch.