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

SQLStatistics

Conformance

Version Introduced: ODBC 1.0
Standards Compliance: ISO 92

Summary

SQLStatistics retrieves a list of statistics about a single table and the indexes associated with the table. The driver returns the information as a result set.

Syntax

SQLRETURN SQLStatistics(
     SQLHSTMT     StatementHandle,
     SQLCHAR *     CatalogName,
     SQLSMALLINT     NameLength1,
     SQLCHAR *     SchemaName,
     SQLSMALLINT     NameLength2,
     SQLCHAR *     TableName,
     SQLSMALLINT     NameLength3,
     SQLUSMALLINT     Unique,
     SQLUSMALLINT     Reserved);

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 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 significant.

NameLength2

[Input]
Length of *SchemaName.

TableName

[Input]
Table name. This argument cannot be a null pointer. SchemaName 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 significant.

NameLength3

[Input]
Length of *TableName.

Unique

[Input]
Type of index: SQL_INDEX_UNIQUE or SQL_INDEX_ALL.

Reserved

[Input]
Indicates the importance of the CARDINALITY and PAGES columns in the result set. The following options affect the return of the CARDINALITY and PAGES columns only; index information is returned even if CARDINALITY and PAGES are not returned.

SQL_ENSURE requests that the driver unconditionally retrieve the statistics. (Drivers that conform only to the X/Open standard and do not support ODBC extensions will not be able to support SQL_ENSURE.)

SQL_QUICK requests that the driver retrieve the CARDINALITY and PAGES only if they are readily available from the server. In this case, the driver does not ensure that the values are current. (Applications that are written to the X/Open standard will always get SQL_QUICK behavior from ODBC 3.x-compliant drivers.)

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_STILL_EXECUTING, SQL_ERROR, or SQL_INVALID_HANDLE.

Diagnostics

When SQLStatistics returns SQL_ERROR or SQL_SUCCESS_WITH_INFO, an associated SQLSTATE value may 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 SQLStatistics 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

SQLStatistics returns information about a single table as a standard result set, ordered by NON_UNIQUE, TYPE, INDEX_QUALIFIER, INDEX_NAME, and ORDINAL_POSITION. The result set combines statistics information (in the CARDINALITY and PAGES columns of the result set) for the table with information about each index. For information about how this information might be used, see "Uses of Catalog Data" in Chapter 7, "Catalog Functions."

To determine the actual lengths of the TABLE_CAT, TABLE_SCHEM, TABLE_NAME, and COLUMN_NAME columns, an application can 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 columns have been renamed for ODBC 3.x. The column name changes do not affect backward compatibility because applications bind by column number.

The following table lists the columns in the result set. Additional columns beyond column 13 (FILTER_CONDITION) 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."

If the row in the result set corresponds to a table, the driver sets TYPE to SQL_TABLE_STAT and sets NON_UNIQUE, INDEX_QUALIFIER, INDEX_NAME, ORDINAL_POSITION, COLUMN_NAME, and ASC_OR_DESC to NULL. If CARDINALITY or PAGES are not available from the data source, the driver sets them to NULL.

Code Example

For a code example of a similar function, see SQLColumns.

Related Functions