Trait odbc_api::ResultSetMetadata

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pub trait ResultSetMetadata: AsStatementRef {
    // Provided methods
    fn describe_col(
        &mut self,
        column_number: u16,
        column_description: &mut ColumnDescription
    ) -> Result<(), Error> { ... }
    fn num_result_cols(&mut self) -> Result<i16, Error> { ... }
    fn column_is_unsigned(&mut self, column_number: u16) -> Result<bool, Error> { ... }
    fn col_octet_length(&mut self, column_number: u16) -> Result<isize, Error> { ... }
    fn col_display_size(&mut self, column_number: u16) -> Result<isize, Error> { ... }
    fn col_precision(&mut self, column_number: u16) -> Result<isize, Error> { ... }
    fn col_scale(&mut self, column_number: u16) -> Result<isize, Error> { ... }
    fn col_name(&mut self, column_number: u16) -> Result<String, Error> { ... }
    fn column_names(&mut self) -> Result<ColumnNamesIt<'_, Self>, Error> { ... }
    fn col_data_type(&mut self, column_number: u16) -> Result<DataType, Error> { ... }
}

Expand description

Provides Metadata of the resulting the result set. Implemented by Cursor types and prepared queries. Fetching metadata from a prepared query might be expensive (driver dependent), so your application should fetch the Metadata it requires from the Cursor if possible.

Provided Methods§

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fn describe_col( &mut self, column_number: u16, column_description: &mut ColumnDescription ) -> Result<(), Error>

Fetch a column description using the column index.

Parameters

column_number: Column index. 0 is the bookmark column. The other column indices start with 1.
column_description: Holds the description of the column after the call. This method does not provide strong exception safety as the value of this argument is undefined in case of an error.

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fn num_result_cols(&mut self) -> Result<i16, Error>

Number of columns in result set. Can also be used to see wether executing a prepared Statement (crate::Prepared) would yield a result set, as this would return 0 if it does not.

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fn column_is_unsigned(&mut self, column_number: u16) -> Result<bool, Error>

true if a given column in a result set is unsigned or not a numeric type, false otherwise.

column_number: Index of the column, starting at 1.

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fn col_octet_length(&mut self, column_number: u16) -> Result<isize, Error>

Returns the size in bytes of the columns. For variable sized types the maximum size is returned, excluding a terminating zero.

column_number: Index of the column, starting at 1.

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fn col_display_size(&mut self, column_number: u16) -> Result<isize, Error>

Maximum number of characters required to display data from the column.

column_number: Index of the column, starting at 1.

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fn col_precision(&mut self, column_number: u16) -> Result<isize, Error>

Precision of the column.

Denotes the applicable precision. For data types SQL_TYPE_TIME, SQL_TYPE_TIMESTAMP, and all the interval data types that represent a time interval, its value is the applicable precision of the fractional seconds component.

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fn col_scale(&mut self, column_number: u16) -> Result<isize, Error>

The applicable scale for a numeric data type. For DECIMAL and NUMERIC data types, this is the defined scale. It is undefined for all other data types.

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fn col_name(&mut self, column_number: u16) -> Result<String, Error>

The column alias, if it applies. If the column alias does not apply, the column name is returned. If there is no column name or a column alias, an empty string is returned.

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