| Specification: | DB2 CLI 2.1 | ODBC 1.0 |
SQLProcedureColumns() returns a list of input and output parameters associated with a procedure. The information is returned in an SQL result set, which can be retrieved using the same functions that are used to process a result set generated by a query.
Syntax
SQLRETURN SQLProcedureColumns(SQLHSTMT StatementHandle, /* hstmt */
SQLCHAR FAR *CatalogName, /* szProcCatalog */
SQLSMALLINT NameLength1, /* cbProcCatalog */
SQLCHAR FAR *SchemaName, /* szProcSchema */
SQLSMALLINT NameLength2, /* cbProcSchema */
SQLCHAR FAR *ProcName, /* szProcName */
SQLSMALLINT NameLength3, /* cbProcName */
SQLCHAR FAR *ColumnName, /* szColumnName */
SQLSMALLINT NameLength4); /* cbColumnName */
Function Arguments
Table 136. SQLProcedureColumns Arguments
| Data Type | Argument | Use | Description |
|---|---|---|---|
| SQLHSTMT | StatementHandle | input | Statement handle. |
| SQLCHAR * | CatalogName | input | Catalog qualifier of a 3 part procedure name.
This must be a NULL pointer or a zero length string. |
| SQLSMALLINT | NameLength1 | input | Length of CatalogName. This must be set to 0. |
| SQLCHAR * | SchemaName | input | Buffer that may contain a pattern-value to qualify the result
set by schema name.
For DB2 for MVS/ESA V 4.1, all the stored procedures are in one schema; the only acceptable value for the SchemaName argument is a null pointer. For DB2 Universal Database, SchemaName can contain a valid pattern value. For more information about valid search patterns, refer to "Querying System Catalog Information". |
| SQLSMALLINT | NameLength2 | input | Length of SchemaName |
| SQLCHAR * | ProcName | input | Buffer that may contain a pattern-value to qualify the result set by procedure name. |
| SQLSMALLINT | NameLength3 | input | Length of ProcName |
| SQLCHAR * | ColumnName | input | Buffer that may contain a pattern-value to qualify the result set by parameter name. This argument is to be used to further qualify the result set already restricted by specifying a non-empty value for ProcName and/or SchemaName. |
| SQLSMALLINT | NameLength4 | input | Length of ColumnName |
Usage
DB2 Universal Database version 5 introduced two system catalog views used to store information about all stored procedures on the server (SYSCAT.PROCEDURES and SYSCAT.PROCPARMS). See Appendix G. "Catalog Views for Stored Procedures" for information on these views.
Before version 5, DB2 CLI used the pseudo catalog table for stored procedure registration. By default, DB2 CLI will use the new system catalog views. If the application expects to use the pseudo catalog table then the CLI/ODBC configuration keyword PATCH1 should be set to 262144. See "Replacement of the Pseudo Catalog Table for Stored Procedures" for more information.
If the stored procedure is at a DB2 for MVS/ESA V 4.1 server or later, the name of the stored procedures must be registered in the server's SYSIBM.SYSPROCEDURES catalog table.
For versions of other DB2 servers that do not provide facilities for a stored procedure catalog, an empty result set will be returned.
DB2 CLI will return information on the input, input/output, and output parameters associated with the stored procedure, but cannot return information on the descriptor information for any result sets returned.
SQLProcedureColumns() returns the information in a result set, ordered by PROCEDURE_CAT, PROCEDURE_SCHEM, PROCEDURE_NAME, and COLUMN_TYPE. Table 137 lists the columns in the result set. Applications should be aware that columns beyond the last column may be defined in future releases.
Since calls to SQLProcedureColumns() in many cases map to a complex and thus expensive query against the system catalog, they should be used sparingly, and the results saved rather than repeating calls.
The VARCHAR columns of the catalog functions result set have been declared with a maximum length attribute of 128 to be consistent with SQL92 limits. Since DB2 names are less than 128, the application can choose to always set aside 128 characters (plus the null-terminator) for the output buffer, or alternatively, 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 to determine respectively the actual lengths of the TABLE_CAT, TABLE_SCHEM, TABLE_NAME, and COLUMN_NAME columns supported by the connected DBMS.
If the SQL_ATTR_LONGDATA_COMPAT connection attribute is set, LOB column types will be reported as LONG VARCHAR, LONG VARBINARY or LONG VARGRAPHIC types.
Although new columns may be added and the names of the existing columns
changed in future releases, the position of the current columns will not
change. There were changes to these columns between version 2 and version 5.
See "Changes to SQLProcedureColumns() Return Values" for more information if you are running a version 2 DB2 CLI application that
uses SQLProcedureColumns(), against a version 5 or later server.
REFID='V3REV2'.
Table 137. Columns Returned By SQLProcedureColumns
| Column Number/Name | Data Type | Description | ||||||
|---|---|---|---|---|---|---|---|---|
| 1 PROCEDURE_CAT | VARCHAR(128) | The is always null. | ||||||
| 2 PROCEDURE_SCHEM | VARCHAR(128) | The name of the schema containing PROCEDURE_NAME. (This is also NULL for DB2 for MVS/ESA V 4.1 SQLProcedureColumns() result sets.) | ||||||
| 3 PROCEDURE_NAME | VARCHAR(128) | Name of the procedure. | ||||||
| 4 COLUMN_NAME | VARCHAR(128) | Name of the parameter. | ||||||
| 5 COLUMN_TYPE | SMALLINT not NULL | Identifies the type information associated with this row. The values can
be:
| ||||||
| 6 DATA_TYPE | SMALLINT not NULL | SQL data type. | ||||||
| 7 TYPE_NAME | VARCHAR(128) not NULL | Character string representing the name of the data type corresponding to DATA_TYPE. | ||||||
| 8 COLUMN_SIZE | INTEGER | If the DATA_TYPE column value denotes a character or binary string, then
this column contains the maximum length in bytes; if it is a graphic (DBCS)
string, this is the number of double byte characters for the parameter.
For date, time, timestamp data types, this is the total number of bytes required to display the value when converted to character. For numeric data types, this is either the total number of digits, or the total number of bits allowed in the column, depending on the value in the NUM_PREC_RADIX column in the result set. See also Table 197. | ||||||
| 9 BUFFER_LENGTH | INTEGER | The maximum number of bytes for the associated C buffer to store data
from this parameter if SQL_C_DEFAULT were specified on the SQLBindCol(),
SQLGetData() and SQLBindParameter() calls. This length
excludes any null-terminator. For exact numeric data types, the length
accounts for the decimal and the sign.
See Table 199. | ||||||
| 10 DECIMAL_DIGITS | SMALLINT | The scale of the parameter. NULL is returned for data types where scale
is not applicable.
See Table 198. | ||||||
| 11 NUM_PREC_RADIX | SMALLINT | Either 10 or 2 or NULL. If DATA_TYPE is an approximate numeric data type,
this column contains the value 2, then the COLUMN_SIZE column contains the
number of bits allowed in the parameter.
If DATA_TYPE is an exact numeric data type, this column contains the value 10 and the COLUMN_SIZE and DECIMAL_DIGITS columns contain the number of decimal digits allowed for the parameter. For numeric data types, the DBMS can return a NUM_PREC_RADIX of either 10 or 2. NULL is returned for data types where radix is not applicable. | ||||||
| 12 NULLABLE | SMALLINT not NULL | SQL_NO_NULLS if the parameter does not accept NULL values.
SQL_NULLABLE if the parameter accepts NULL values. | ||||||
| 13 REMARKS | VARCHAR(254) | May contain descriptive information about the parameter. | ||||||
| 14 COLUMN_DEF | VARCHAR | The default value of the column.
If NULL was specified as the default value, then this column is the word NULL, not enclosed in quotation marks. If the default value cannot be represented without truncation, then this column contains TRUNCATED, with no enclosing single quotation marks. If no default value was specified, then 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. | ||||||
| 15 SQL_DATA_TYPE | 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 data types (DB2 CLI does not support interval data types).
For datetime data types, the SQL_DATA_TYPE field in the result set will be SQL_DATETIME, and the SQL_DATETIME_SUB field will return the subcode for the specific datetime data type (SQL_CODE_DATE, SQL_CODE_TIME or SQL_CODE_TIMESTAMP). | ||||||
| 16 SQL_DATETIME_SUB | SMALLINT | The subtype code for datetime data types. For all other data types this column returns a NULL (including interval data types which DB2 CLI does not support). | ||||||
| 17 CHAR_OCTET_LENGTH | INTEGER | The maximum length in bytes of a character data type column. For all other data types, this column returns a NULL. | ||||||
| 18 ORDINAL_POSITION | INTEGER NOT NULL | Contains the ordinal position of the parameter given by COLUMN_NAME in this result set. This is the ordinal position of the argument to be provided on the CALL statement. The leftmost argument has an ordinal position of 1. | ||||||
| 19 IS_NULLABLE | Varchar |
An ISO SQL-compliant DBMS cannot return an empty string. The value returned for this column is different than the value returned for
the NULLABLE column. (See the description of the NULLABLE
column.)
| ||||||
| ||||||||
Return Codes
Diagnostics
Table 138. SQLProcedureColumns SQLSTATEs
| SQLSTATE | Description | Explanation |
|---|---|---|
| 24000 | Invalid cursor state. | A cursor was already opened on the statement handle. |
| 40003 08S01 | Communication link failure. | The communication link between the application and data source failed before the function completed. |
| 42601 | PARMLIST syntax error. | The PARMLIST value in the stored procedures catalog table contains a syntax error. |
| HY001 | Memory allocation failure. | DB2 CLI is 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() was called on the StatementHandle. Then the function was called again on the StatementHandle. The function was called and, before it completed execution,
SQLCancel() was called on the StatementHandle from a
different thread in a multithread application.
|
| HY010 | Function sequence error. |
The function was called while in a data-at-execute (SQLParamData(), SQLPutData()) operation. The function was called while within a BEGIN COMPOUND and END COMPOUND SQL operation. An asynchronously executing function (not this one) was called for the
StatementHandle and was still executing when this function was
called.
|
| HY014 | No more handles. | DB2 CLI was unable to allocate a handle due to internal resources. |
| HY090 | Invalid String or Buffer Length | The value of one of the name length arguments was less than 0, but not equal SQL_NTS. |
| HYC00 | Driver not capable. | DB2 CLI does not support catalog as a qualifier for procedure
name.
The connected server does not support schema as a qualifier for procedure name. |
| HYT00 | Timeout expired. | The timeout period expired before the data source returned the result set. Timeouts are only supported on non-multitasking systems such as Windows 3.1 and Macintosh System 7. The timeout period can be set using the SQL_ATTR_QUERY_TIMEOUT attribute for SQLSetConnectAttr(). |
Restrictions
SQLProcedureColumns() does not return information about the attributes of result sets that may be returned from stored procedures.
If an application is connected to a DB2 server that does not provide support for a stored procedure catalog, or does not provide support for stored procedures, SQLProcedureColumns() will return an empty result set.
/* From CLI sample proccols.c */
/* ... */
printf("Enter Procedure Schema Name Search Pattern:\n");
gets((char *)proc_schem.s);
printf("Enter Procedure Name Search Pattern:\n");
gets((char *)proc_name.s);
rc = SQLProcedureColumns(hstmt, NULL, 0, proc_schem.s, SQL_NTS,
proc_name.s, SQL_NTS, (SQLCHAR *)"%", SQL_NTS);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 2, SQL_C_CHAR, (SQLPOINTER) proc_schem.s, 129,
&proc_schem.ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 3, SQL_C_CHAR, (SQLPOINTER) proc_name.s, 129,
&proc_name.ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 4, SQL_C_CHAR, (SQLPOINTER) column_name.s, 129,
&column_name.ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 5, SQL_C_SHORT, (SQLPOINTER) &arg_type,
0, &arg_type_ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 7, SQL_C_CHAR, (SQLPOINTER) type_name.s, 129,
&type_name.ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 8, SQL_C_LONG, (SQLPOINTER) & length,
0, &length_ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 10, SQL_C_SHORT, (SQLPOINTER) &scale,
0, &scale_ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
rc = SQLBindCol(hstmt, 13, SQL_C_CHAR, (SQLPOINTER) remarks.s, 255,
&remarks.ind);
CHECK_HANDLE( SQL_HANDLE_STMT, hstmt, rc ) ;
/* Fetch each row, and display */
while ((rc = SQLFetch(hstmt)) == SQL_SUCCESS) {
sprintf((char *)cur_name, "%s.%s", proc_schem.s, proc_name.s);
if (strcmp((char *)cur_name, (char *)pre_name) != 0) {
printf("\n%s\n", cur_name);
}
strcpy((char *)pre_name, (char *)cur_name);
printf(" %s", column_name.s);
switch (arg_type)
{ case SQL_PARAM_INPUT : printf(", Input"); break;
case SQL_PARAM_OUTPUT : printf(", Output"); break;
case SQL_PARAM_INPUT_OUTPUT : printf(", Input_Output"); break;
}
printf(", %s", type_name.s);
printf(" (%ld", length);
if (scale_ind != SQL_NULL_DATA) {
printf(", %d)\n", scale);
} else {
printf(")\n");
}
if (remarks.ind > 0 ) {
printf("(remarks), %s)\n", remarks.s);
}
} /* endwhile */
References