MDAC 2.5 SDK - ODBC Programmer's Reference
Chapter 21: ODBC API Reference

SQLPrimaryKeys

Conformance

Version Introduced: ODBC 1.0
Standards Compliance: ODBC

Summary

SQLPrimaryKeys returns the column names that make up the primary key for a table. The driver returns the information as a result set. This function does not support returning primary keys from multiple tables in a single call.

Syntax

SQLRETURN SQLPrimaryKeys(
     SQLHSTMT     StatementHandle,
     SQLCHAR *     CatalogName,
     SQLSMALLINT     NameLength1,
     SQLCHAR *     SchemaName,
     SQLSMALLINT     NameLength2,
     SQLCHAR *     TableName,
     SQLSMALLINT     NameLength3);

Arguments

StatementHandle

[Input]
Statement handle.

CatalogName

[Input]
Catalog name. If a driver supports catalogs for some tables but not for others, such as when the driver retrieves data from different DBMSs, an empty string ("") denotes those tables that do not have catalogs. CatalogName cannot contain a string search pattern.

If the SQL_ATTR_METADATA_ID statement attribute is set to SQL_TRUE, CatalogName is treated as an identifier and its case is not significant. If it is SQL_FALSE, CatalogName is an ordinary argument; it is treated literally, and its case is significant. For more information, see "Arguments in Catalog Functions" in Chapter 7, "Catalog Functions."

NameLength1

[Input]
Length in bytes of *CatalogName.

SchemaName

[Input]
Schema name. If a driver supports schemas for some tables but not for others, such as when the driver retrieves data from different DBMSs, an empty string ("") denotes those tables that do not have schemas. SchemaName cannot contain a string search pattern.

If the SQL_ATTR_METADATA_ID statement attribute is set to SQL_TRUE, SchemaName is treated as an identifier and its case is not significant. If it is SQL_FALSE, SchemaName is an ordinary argument; it is treated literally, and its case is not significant.

NameLength2

[Input]
Length in bytes of *SchemaName.

TableName

[Input]
Table name. This argument cannot be a null pointer. TableName cannot contain a string search pattern.

If the SQL_ATTR_METADATA_ID statement attribute is set to SQL_TRUE, TableName is treated as an identifier and its case is not significant. If it is SQL_FALSE, TableName is an ordinary argument; it is treated literally, and its case is not significant.

NameLength3

[Input]
Length in bytes of *TableName.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_STILL_EXECUTING, SQL_ERROR, or SQL_INVALID_HANDLE.

Diagnostics

When SQLPrimaryKeys returns SQL_ERROR or SQL_SUCCESS_WITH_INFO, an associated SQLSTATE value can be obtained by calling SQLGetDiagRec with a HandleType of SQL_HANDLE_STMT and a Handle of StatementHandle. The following table lists the SQLSTATE values commonly returned by SQLPrimaryKeys and explains each one in the context of this function; the notation "(DM)" precedes the descriptions of SQLSTATEs returned by the Driver Manager. The return code associated with each SQLSTATE value is SQL_ERROR, unless noted otherwise.

Comments

SQLPrimaryKeys returns the results as a standard result set, ordered by TABLE_CAT, TABLE_SCHEM, TABLE_NAME, and KEY_SEQ. For information about how this information might be used, see "Uses of Catalog Data" in Chapter 7, "Catalog Functions."

The following columns have been renamed for ODBC 3.x. The column name changes do not affect backward compatibility because applications bind by column number.

To determine the actual lengths of the TABLE_CAT, TABLE_SCHEM, TABLE_NAME, and COLUMN_NAME columns, call SQLGetInfo with the SQL_MAX_CATALOG_NAME_LEN, SQL_MAX_SCHEMA_NAME_LEN, SQL_MAX_TABLE_NAME_LEN, and SQL_MAX_COLUMN_NAME_LEN options.

Note   For more information about the general use, arguments, and returned data of ODBC catalog functions, see Chapter 7, "Catalog Functions."

The following table lists the columns in the result set. Additional columns beyond column 6 (PK_NAME) can be defined by the driver. An application should gain access to driver-specific columns by counting down from the end of the result set rather than specifying an explicit ordinal position. For more information, see "Data Returned by Catalog Functions" in Chapter 7, "Catalog Functions."

Code Example

See SQLForeignKeys.

Related Functions