Struct ibm_db::Statement [−][src]
pub struct Statement<'a, 'b, S, R, AC: AutocommitMode> { /* fields omitted */ }
Expand description
A Statement
can be used to execute queries and retrieves results.
Implementations
Binds a parameter to a parameter marker in an SQL statement.
Result
This method will destroy the statement and create a new one which may not outlive the bound parameter. This is to ensure that the statement will not dereference an invalid pointer during execution.
Arguments
parameter_index
- Index of the marker to bind to the parameter. Starting at1
value
- Reference to bind to the marker
Example
let conn = env.connect("TestDataSource", "", "")?; let stmt = Statement::with_parent(&conn)?; let param = 1968; let stmt = stmt.bind_parameter(1, ¶m)?; let sql_text = "SELECT TITLE FROM MOVIES WHERE YEAR = ?"; if let Data(mut stmt) = stmt.exec_direct(sql_text)? { // ... }
Prepares a statement for execution. Executing a prepared statement is faster than directly executing an unprepared statement, since it is already compiled into an Access Plan. This makes preparing statement a good idea if you want to repeatedly execute a query with a different set of parameters and care about performance.
Example
let conn = env.connect("TestDataSource", "", "")?; let stmt = Statement::with_parent(&conn)?; let mut stmt = stmt.prepare("SELECT TITLE FROM MOVIES WHERE YEAR = ?")?; fn print_one_movie_from<'a> (year: u16, stmt: Statement<'a,'a, Prepared, NoResult, safe::AutocommitOn>) -> Result<Statement<'a, 'a, Prepared, NoResult, safe::AutocommitOn>>{ let stmt = stmt.bind_parameter(1, &year)?; let stmt = if let Data(mut stmt) = stmt.execute()?{ if let Some(mut cursor) = stmt.fetch()?{ println!("{}", cursor.get_data::<String>(1)?.unwrap()); } stmt.close_cursor()? } else { panic!("SELECT statement returned no result set"); }; stmt.reset_parameters() }; for year in 1990..2010{ stmt = print_one_movie_from(year, stmt)? }
Prepares a statement for execution. Executing a prepared statement is faster than directly executing an unprepared statement, since it is already compiled into an Access Plan. This makes preparing statement a good idea if you want to repeatedly execute a query with a different set of parameters and care about performance.
Example
let env = create_environment_v3().map_err(|e| e.unwrap())?; let conn = env.connect("TestDataSource", "", "")?; let stmt = Statement::with_parent(&conn)?; // need encode_rs crate // let mut stmt = stmt.prepare_bytes(&GB2312.encode("select '你好' as hello").0)?;
The number of columns in a result set
Can be called successfully only when the statement is in the prepared, executed, or positioned state. If the statement does not return columns the result will be 0.
Returns description struct for result set column with a given index. Note: indexing is starting from 1.
pub fn tables(
self,
catalog_name: &String,
schema_name: &String,
table_name: &String,
table_type: &String
) -> Result<Statement<'a, 'b, Executed, HasResult, AC>, Box<dyn Error>>
pub fn tables_str(
self,
catalog_name: &str,
schema_name: &str,
table_name: &str,
table_type: &str
) -> Result<Statement<'a, 'b, Executed, HasResult, AC>, Box<dyn Error>>
pub fn tables_opt_str(
self,
catalog_name: Option<&str>,
schema_name: Option<&str>,
table_name: Option<&str>,
table_type: &str
) -> Result<Statement<'a, 'b, Executed, HasResult, AC>, Box<dyn Error>>
pub fn exec_direct(
self,
statement_text: &str
) -> Result<ResultSetState<'a, 'b, Executed, AC>, Box<dyn Error>>
pub fn exec_direct(
self,
statement_text: &str
) -> Result<ResultSetState<'a, 'b, Executed, AC>, Box<dyn Error>>
Executes a preparable statement, using the current values of the parameter marker variables if any parameters exist in the statement.
SQLExecDirect
is the fastest way to submit an SQL statement for one-time execution.
pub fn exec_direct_bytes(
self,
bytes: &[u8]
) -> Result<ResultSetState<'a, 'b, Executed, AC>, Box<dyn Error>>
pub fn exec_direct_bytes(
self,
bytes: &[u8]
) -> Result<ResultSetState<'a, 'b, Executed, AC>, Box<dyn Error>>
Executes a preparable statement, using the current values of the parameter marker variables if any parameters exist in the statement.
SQLExecDirect
is the fastest way to submit an SQL statement for one-time execution.
The number of columns in a result set
Can be called successfully only when the statement is in the prepared, executed, or positioned state. If the statement does not return columns the result will be 0.
Returns description struct for result set column with a given index. Note: indexing is starting from 1.
Fetches the next rowset of data from the result set and returns data for all bound columns.
Call this method to reuse the statement to execute another query.
For many drivers allocating new statements is expensive. So reusing a Statement
is usually
more efficient than freeing an existing and allocating a new one. However to reuse a
statement any open result sets must be closed.
Only call this method if you have already read the result set returned by the previous
query, or if you do no not intend to read it.
Example
let conn = env.connect("TestDataSource", "", "")?; let stmt = Statement::with_parent(&conn)?; let stmt = match stmt.exec_direct("CREATE TABLE STAGE (A TEXT, B TEXT);")?{ // Some drivers will return an empty result set. We need to close it before we can use // statement again. Data(stmt) => stmt.close_cursor()?, NoData(stmt) => stmt, }; let stmt = stmt.exec_direct("INSERT INTO STAGE (A, B) VALUES ('Hello', 'World');")?; //...
Trait Implementations
Used to identify the type of the handle in various functions of the ODBC C interface
Auto Trait Implementations
impl<'a, 'b, S, R, AC> RefUnwindSafe for Statement<'a, 'b, S, R, AC> where
AC: RefUnwindSafe,
R: RefUnwindSafe,
S: RefUnwindSafe,
impl<'a, 'b, S, R, AC> UnwindSafe for Statement<'a, 'b, S, R, AC> where
AC: UnwindSafe,
R: UnwindSafe,
S: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
pub fn diagnostics(
&self,
rec_number: i16,
message_text: &mut [u8]
) -> ReturnOption<DiagResult, ()>
pub fn diagnostics(
&self,
rec_number: i16,
message_text: &mut [u8]
) -> ReturnOption<DiagResult, ()>
Returns the current values of multiple fields of a diagnostic record that contains error, warning, and status information. Read more
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
pub fn vzip(self) -> V