SQLProcedureColumns Function

Conformance
Version Introduced: ODBC 1.0 Standards Compliance: ODBC

Summary
SQLProcedureColumns returns the list of input and output parameters, as well as the columns that make up the result set for the specified procedures. The driver returns the information as a result set on the specified statement.

Syntax

  
SQLRETURN SQLProcedureColumns(  
     SQLHSTMT      StatementHandle,  
     SQLCHAR *     CatalogName,  
     SQLSMALLINT   NameLength1,  
     SQLCHAR *     SchemaName,  
     SQLSMALLINT   NameLength2,  
     SQLCHAR *     ProcName,  
     SQLSMALLINT   NameLength3,  
     SQLCHAR *     ColumnName,  
     SQLSMALLINT   NameLength4);  

Arguments

StatementHandle
[Input] Statement handle.

CatalogName
[Input] Procedure catalog name. If a driver supports catalogs for some procedures but not for others, such as when the driver retrieves data from different DBMSs, an empty string ("") denotes those procedures 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.

NameLength1
[Input] Length in characters of *CatalogName.

SchemaName
[Input] String search pattern for procedure schema names. If a driver supports schemas for some procedures but not for others, such as when the driver retrieves data from different DBMSs, an empty string ("") denotes those procedures that do not have schemas.

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 a pattern value argument; it is treated literally, and its case is significant.

NameLength2
[Input] Length in characters of *SchemaName.

ProcName
[Input] String search pattern for procedure names.

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

NameLength3
[Input] Length in characters of *ProcName.

ColumnName
[Input] String search pattern for column names.

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

NameLength4
[Input] Length in characters of *ColumnName.

Returns

SQL_SUCCESS, SQL_SUCCESS_WITH_INFO, SQL_STILL_EXECUTING, SQL_ERROR, or SQL_INVALID_HANDLE.

Diagnostics

When SQLProcedureColumns 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 SQLProcedureColumns 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.

SQLSTATE	Error	Description
01000	General warning	Driver-specific informational message. (Function returns SQL_SUCCESS_WITH_INFO.)
08S01	Communication link failure	The communication link between the driver and the data source to which the driver was connected failed before the function completed processing.
24000	Invalid cursor state	A cursor was open on the StatementHandle, and SQLFetch or SQLFetchScroll had been called. This error is returned by the Driver Manager if SQLFetch or SQLFetchScroll has not returned SQL_NO_DATA, and is returned by the driver if SQLFetch or SQLFetchScroll has returned SQL_NO_DATA. A cursor was open on the StatementHandle, but SQLFetch or SQLFetchScroll had not been called.
40001	Serialization failure	The transaction was rolled back due to a resource deadlock with another transaction.
40003	Statement completion unknown	The associated connection failed during the execution of this function, and the state of the transaction cannot be determined.
HY000	General error	An error occurred for which there was no specific SQLSTATE and for which no implementation-specific SQLSTATE was defined. The error message returned by SQLError in the *MessageText buffer describes the error and its cause.
HY001	Memory allocation error	The driver was unable to allocate memory required to support execution or completion of the function.
HY008	Operation canceled	Asynchronous processing was enabled for the StatementHandle. The function was called, and before it completed execution, SQLCancel or SQLCancelHandle was called on the StatementHandle. Then the function was called again on the StatementHandle. The function was called, and before it completed execution, SQLCancel or SQLCancelHandle was called on the StatementHandle from a different thread in a multithread application.
HY009	Invalid use of null pointer	The SQL_ATTR_METADATA_ID statement attribute was set to SQL_TRUE, the CatalogName argument was a null pointer, and the SQL_CATALOG_NAME InfoType returns that catalog names are supported. (DM) The SQL_ATTR_METADATA_ID statement attribute was set to SQL_TRUE, and the SchemaName, ProcName, or ColumnName argument was a null pointer.
HY010	Function sequence error	(DM) An asynchronously executing function was called for the connection handle that is associated with the StatementHandle. This aynschronous function was still executing when the SQLProcedureColumns function was called. (DM) SQLExecute, SQLExecDirect, or SQLMoreResults was called for the StatementHandle and returned SQL_PARAM_DATA_AVAILABLE. This function was called before data was retrieved for all streamed parameters. (DM) An asynchronously executing function (not this one) was called for the StatementHandle and was still executing when this function was called. (DM) SQLExecute, SQLExecDirect, SQLBulkOperations, or SQLSetPos was called for the StatementHandle and returned SQL_NEED_DATA. This function was called before data was sent for all data-at-execution parameters or columns.
HY090	Invalid string or buffer length	(DM) The value of one of the name length arguments was less than 0 but not equal to SQL_NTS. The value of one of the name length arguments exceeded the maximum length value for the corresponding catalog, schema, procedure, or column name.
HY117	Connection is suspended due to unknown transaction state. Only disconnect and read-only functions are allowed.	(DM) For more information about suspended state, see SQLEndTran Function.
HYC00	Optional feature not implemented	A procedure catalog was specified, and the driver or data source does not support catalogs. A procedure schema was specified, and the driver or data source does not support schemas. A string search pattern was specified for the procedure schema, procedure name, or column name, and the data source does not support search patterns for one or more of those arguments. The combination of the current settings of the SQL_ATTR_CONCURRENCY and SQL_ATTR_CURSOR_TYPE statement attributes was not supported by the driver or data source. The SQL_ATTR_USE_BOOKMARKS statement attribute was set to SQL_UB_VARIABLE, and the SQL_ATTR_CURSOR_TYPE statement attribute was set to a cursor type for which the driver does not support bookmarks.
HYT00	Timeout expired	The timeout period expired before the data source returned the result set. The timeout period is set through SQLSetStmtAttr, SQL_ATTR_QUERY_TIMEOUT.
HYT01	Connection timeout expired	The connection timeout period expired before the data source responded to the request. The connection timeout period is set through SQLSetConnectAttr, SQL_ATTR_CONNECTION_TIMEOUT.
IM001	Driver does not support this function	(DM) The driver associated with the StatementHandle does not support the function.
IM017	Polling is disabled in asynchronous notification mode	Whenever the notification model is used, polling is disabled.
IM018	SQLCompleteAsync has not been called to complete the previous asynchronous operation on this handle.	If the previous function call on the handle returns SQL_STILL_EXECUTING and if notification mode is enabled, SQLCompleteAsync must be called on the handle to do post-processing and complete the operation.

Comments

This function is typically used before statement execution to retrieve information about procedure parameters and the columns that make up the result set or sets returned by the procedure, if any. For more information, see Procedures.

Note

SQLProcedureColumns might not return all columns used by a procedure. For example, a driver might return only information about the parameters used by a procedure and not the columns in a result set it generates.

The SchemaName, ProcName, and ColumnName arguments accept search patterns. For more information about valid search patterns, see Pattern Value Arguments.

Note

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

SQLProcedureColumns returns the results as a standard result set, ordered by PROCEDURE_CAT, PROCEDURE_SCHEM, PROCEDURE_NAME, and COLUMN_TYPE. Column names are returned for each procedure in the following order: the name of the return value, the names of each parameter in the procedure invocation (in call order), and then the names of each column in the result set returned by the procedure (in column order).

Applications should bind driver-specific columns relative to the end of the result set. For more information, see Data Returned by Catalog Functions.

To determine the actual lengths of the PROCEDURE_CAT, PROCEDURE_SCHEM, PROCEDURE_NAME, and COLUMN_NAME columns, an application can call SQLGetInfo with the SQL_MAX_CATALOG_NAME_LEN, SQL_MAX_SCHEMA_NAME_LEN, SQL_MAX_PROCEDURE_NAME_LEN, and SQL_MAX_COLUMN_NAME_LEN options.

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.

ODBC 2.0 column	ODBC 3.x column
PROCEDURE_QUALIFIER	PROCEDURE_CAT
PROCEDURE _OWNER	PROCEDURE_SCHEM
PRECISION	COLUMN_SIZE
LENGTH	BUFFER_LENGTH
SCALE	DECIMAL_DIGITS
RADIX	NUM_PREC_RADIX

The following columns have been added to the results set returned by SQLProcedureColumns for ODBC 3.x:

• COLUMN_DEF

• DATETIME_CODE

• CHAR_OCTET_LENGTH

• ORDINAL_POSITION

• IS_NULLABLE

The following table lists the columns in the result set. Additional columns beyond column 19 (IS_NULLABLE) 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.

Column name	Column number	Data type	Comments
PROCEDURE_CAT (ODBC 2.0)	1	Varchar	Procedure catalog name; NULL if not applicable to the data source. If a driver supports catalogs for some procedures but not for others, such as when the driver retrieves data from different DBMSs, it returns an empty string ("") for those procedures that do not have catalogs.
PROCEDURE_SCHEM (ODBC 2.0)	2	Varchar	Procedure schema name; NULL if not applicable to the data source. If a driver supports schemas for some procedures but not for others, such as when the driver retrieves data from different DBMSs, it returns an empty string ("") for those procedures that do not have schemas.
PROCEDURE_NAME (ODBC 2.0)	3	Varchar not NULL	Procedure name. An empty string is returned for a procedure that does not have a name.
COLUMN_NAME (ODBC 2.0)	4	Varchar not NULL	Procedure column name. The driver returns an empty string for a procedure column that does not have a name.
COLUMN_TYPE (ODBC 2.0)	5	Smallint not NULL	Defines the procedure column as a parameter or a result set column: SQL_PARAM_TYPE_UNKNOWN: The procedure column is a parameter whose type is unknown. (ODBC 1.0) SQL_PARAM_INPUT: The procedure column is an input parameter. (ODBC 1.0) SQL_PARAM_INPUT_OUTPUT: The procedure column is an input/output parameter. (ODBC 1.0) SQL_PARAM_OUTPUT: The procedure column is an output parameter. (ODBC 2.0) SQL_RETURN_VALUE: The procedure column is the return value of the procedure. (ODBC 2.0) SQL_RESULT_COL: The procedure column is a result set column. (ODBC 1.0)
DATA_TYPE (ODBC 2.0)	6	Smallint not NULL	SQL data type. This can be an ODBC SQL data type or a driver-specific SQL data type. For datetime and interval data types, this column returns the concise data types (for example, SQL_TYPE_TIME or SQL_INTERVAL_YEAR_TO_MONTH). For a list of valid ODBC SQL data types, see SQL Data Types in Appendix D: Data Types. For information about driver-specific SQL data types, see the driver's documentation.
TYPE_NAME (ODBC 2.0)	7	Varchar not NULL	Data source-dependent data type name; for example, "CHAR", "VARCHAR", "MONEY", "LONG VARBINARY", or "CHAR ( ) FOR BIT DATA".
COLUMN_SIZE (ODBC 2.0)	8	Integer	The column size of the procedure column on the data source. NULL is returned for data types where column size is not applicable. For more information concerning precision, see Column Size, Decimal Digits, Transfer Octet Length, and Display Size in Appendix D: Data Types.
BUFFER_LENGTH (ODBC 2.0)	9	Integer	The length in bytes of data transferred on an SQLGetData or SQLFetch operation if SQL_C_DEFAULT is specified. For numeric data, this size may be different than the size of the data stored on the data source. For more information, see Column Size, Decimal Digits, Transfer Octet Length, and Display Size, in Appendix D: Data Types.
DECIMAL_DIGITS (ODBC 2.0)	10	Smallint	The decimal digits of the procedure column on the data source. NULL is returned for data types where decimal digits is not applicable. For more information concerning decimal digits, see Column Size, Decimal Digits, Transfer Octet Length, and Display Size, in Appendix D: Data Types.
NUM_PREC_RADIX (ODBC 2.0)	11	Smallint	For numeric data types, either 10 or 2. If 10, the values in COLUMN_SIZE and DECIMAL_DIGITS give the number of decimal digits allowed for the column. For example, a DECIMAL(12,5) column would return a NUM_PREC_RADIX of 10, a COLUMN_SIZE of 12, and a DECIMAL_DIGITS of 5; a FLOAT column could return a NUM_PREC_RADIX of 10, a COLUMN_SIZE of 15, and a DECIMAL_DIGITS of NULL. If 2, the values in COLUMN_SIZE and DECIMAL_DIGITS give the number of bits allowed in the column. For example, a FLOAT column could return a NUM_PREC_RADIX of 2, a COLUMN_SIZE of 53, and a DECIMAL_DIGITS of NULL. NULL is returned for data types where NUM_PREC_RADIX is not applicable.
NULLABLE (ODBC 2.0)	12	Smallint not NULL	Whether the procedure column accepts a NULL value: SQL_NO_NULLS: The procedure column does not accept NULL values. SQL_NULLABLE: The procedure column accepts NULL values. SQL_NULLABLE_UNKNOWN: It is not known if the procedure column accepts NULL values.
REMARKS (ODBC 2.0)	13	Varchar	A description of the procedure column.
COLUMN_DEF (ODBC 3.0)	14	Varchar	The default value of the column. If NULL was specified as the default value, this column is the word NULL, not enclosed in quotation marks. If the default value cannot be represented without truncation, this column contains TRUNCATED, with no enclosing single quotation marks. If no default value was specified, this column is NULL. The value of COLUMN_DEF can be used in generating a new column definition, except when it contains the value TRUNCATED.
SQL_DATA_TYPE (ODBC 3.0)	15	Smallint not NULL	The value of the SQL data type as it appears in the SQL_DESC_TYPE field of the descriptor. This column is the same as the DATA_TYPE column, except for datetime and interval data types. For datetime and interval data types, the SQL_DATA_TYPE field in the result set will return SQL_INTERVAL or SQL_DATETIME, and the SQL_DATETIME_SUB field will return the subcode for the specific interval or datetime data type. (See Appendix D: Data Types.)
SQL_DATETIME_SUB (ODBC 3.0)	16	Smallint	The subtype code for datetime and interval data types. For other data types, this column returns a NULL.
CHAR_OCTET_LENGTH (ODBC 3.0)	17	Integer	The maximum length in bytes of a character or binary data type column. For all other data types, this column returns a NULL.
ORDINAL_POSITION (ODBC 3.0)	18	Integer not NULL	For input and output parameters, the ordinal position of the parameter in the procedure definition (in increasing parameter order, starting at 1). For a return value (if any), 0 is returned. For result-set columns, the ordinal position of the column in the result set, with the first column in the result set being number 1. If there are multiple result sets, column ordinal positions are returned in a driver-specific manner.
IS_NULLABLE (ODBC 3.0)	19	Varchar	"NO" if the column does not include NULLs. "YES" if the column can include NULLs. This column returns a zero-length string if nullability is unknown. ISO rules are followed to determine nullability. An ISO SQL-compliant DBMS cannot return an empty string. The value returned for this column is different from the value returned for the NULLABLE column. (See the description of the NULLABLE column.)

Code Example

See Procedure Calls.

Related Functions

For information about	See
Binding a buffer to a column in a result set	SQLBindCol Function
Canceling statement processing	SQLCancel Function
Fetching a single row or a block of data in a forward-only direction	SQLFetch Function
Fetching a block of data or scrolling through a result set	SQLFetchScroll Function
Returning a list of procedures in a data source	SQLProcedures Function

See Also

ODBC API Reference
ODBC Header Files