Attached is a patch for DBI which defines the column_info
interface.
Steffen
*** DBI-1.20/DBI.pm Sat Aug 25 01:33:52 2001
--- DBI.pm Sat Oct 20 19:19:07 2001
***************
*** 296,301 ****
--- 296,302 ----
tables => { U =>[1,6,'$catalog, $schema, $table, $type [, \%attr ]' ]
},
table_info => { U =>[1,6,'$catalog, $schema, $table, $type [, \%attr ]' ]
},
+ column_info => { U =>[1,6,'$catalog, $schema, $table, $column [, \%attr ]'
+] },
primary_key_info=> { U =>[4,5,'$catalog, $schema, $table [, \%attr ]' ] },
primary_key => { U =>[4,5,'$catalog, $schema, $table [, \%attr ]' ] },
type_info_all => { U =>[1,1] },
***************
*** 1068,1073 ****
--- 1069,1078 ----
shift->_not_impl('table_info');
}
+ sub column_info {
+ shift->_not_impl('column_info');
+ }
+
sub primary_key_info {
shift->_not_impl('primary_key_info');
}
***************
*** 2719,2724 ****
--- 2724,2850 ----
be part of the Data Access SDK.
See also page 306 of the (very large) SQL/CLI specification:
+
+
+http://www.jtc1sc32.org/sc32/jtc1sc32.nsf/Attachments/DF86E81BE70151D58525699800643F56/$FILE/32N0595T.PDF
+
+
+ =item C<column_info> I<NEW>
+
+ B<Warning:> This method is experimental and may change.
+
+ $sth = $dbh->column_info( $catalog, $schema, $table, $column );
+
+ Returns an active statement handle that can be used to fetch
+ information about columns in specified tables.
+
+ The arguments $schema, $table and $column may accept search patterns
+ according to the database/driver, for example: $table = '%FOO%';
+
+ Note: The support for the selection criteria is driver specific. If the
+ driver doesn't support one or more of them then you may get back more
+ than you asked for and can do the filtering yourself.
+
+ The statement handle returned has at least the following fields in the
+ order shown below. Other fields, after these, may also be present.
+
+ B<TABLE_CAT>: The catalog identifier.
+ This field is NULL (C<undef>) if not applicable to the data source,
+ which is often the case. This field is empty if not applicable to the
+ table.
+
+ B<TABLE_SCHEM>: The schema identifier.
+ This field is NULL (C<undef>) if not applicable to the data source,
+ and empty if not applicable to the table.
+
+ B<TABLE_NAME>: The table identifier.
+ Note: A driver may provide column metadata not only for base tables, but
+ also for derived objects like SYNONYMS etc.
+
+ B<COLUMN_NAME>: The column identifier.
+
+ B<DATA_TYPE>: The concise data type code.
+
+ B<TYPE_NAME>: A data source dependent data type name.
+
+ B<COLUMN_SIZE>: The column size.
+ This is the maximum length in characters for character data types,
+ the number of digits or bits for numeric data types or the length
+ in the representation of temporal types.
+ See the relevant specifications for detailed information.
+
+ B<BUFFER_LENGTH>: The length in bytes of transferred data.
+
+ B<DECIMAL_DIGITS>: The total number of significant digits to the right of
+ the decimal point.
+
+ B<NUM_PREC_RADIX>: The radix for numeric precision.
+ The value is 10 or 2 for numeric data types and NULL (C<undef>) if not
+ applicable.
+
+ B<NULLABLE>: Indicates if a column can accept NULLs.
+ The following codes are defined:
+
+ SQL_NO_NULLS 0
+ SQL_NULLABLE 1
+ SQL_NULLABLE_UNKNOWN 2
+
+ B<REMARKS>: A description of the column.
+
+ B<COLUMN_DEF>: The default value of the column.
+
+ B<SQL_DATA_TYPE>: The SQL data type.
+
+ B<SQL_DATETIME_SUB>: The subtype code for datetime and interval data types.
+
+ B<CHAR_OCTET_LENGTH>: The maximum length in bytes of a character or binary
+ data type column.
+
+ B<ORDINAL_POSITION>: The column sequence number (starting with 1).
+
+ B<IS_NULLABLE>: Indicates if the column can accept NULLs.
+ Possible values are: 'NO', 'YES' and ''.
+
+ SQL/CLI defines the following additional columns:
+
+ CHAR_SET_CAT
+ CHAR_SET_SCHEM
+ CHAR_SET_NAME
+ COLLATION_CAT
+ COLLATION_SCHEM
+ COLLATION_NAME
+ UDT_CAT
+ UDT_SCHEM
+ UDT_NAME
+ DOMAIN_CAT
+ DOMAIN_SCHEM
+ DOMAIN_NAME
+ SCOPE_CAT
+ SCOPE_SCHEM
+ SCOPE_NAME
+ MAX_CARDINALITY
+ DTD_IDENTIFIER
+ IS_SELF_REF
+
+ The result set is ordered by TABLE_CAT, TABLE_SCHEM, TABLE_NAME
+ and ORDINAL_POSITION.
+
+ Note: There is some overlap with statement attributes (in perl) and
+ SQLDescribeCol (in ODBC). However, SQLColumns provides more metadata.
+
+ For more detailed information about the fields and their meanings,
+ you can refer to:
+
+ http://msdn.microsoft.com/library/en-us/odbc/htm/odbcsqlcolumns.asp
+
+ If that URL ceases to work then use the MSDN search facility at:
+
+ http://search.microsoft.com/us/dev/
+
+ and search for C<SQLColumns returns> using the exact phrase option.
+ The link you want will probably just be called C<SQLColumns> and will
+ be part of the Data Access SDK.
+
+ See also page 135 of the current SQL/CLI Working Draft:
http://www.jtc1sc32.org/sc32/jtc1sc32.nsf/Attachments/DF86E81BE70151D58525699800643F56/$FILE/32N0595T.PDF
