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 that is generated by a query.
SQLRETURN SQLProcedureColumns(SQLHSTMT StatementHandle,
SQLCHAR *CatalogName,
SQLSMALLINT NameLength1,
SQLCHAR *SchemaName,
SQLSMALLINT NameLength2,
SQLCHAR *ProcName,
SQLSMALLINT NameLength3,
SQLCHAR *ColumnName,
SQLSMALLINT NameLength4);
| Data type | Argument | Use | Description |
|---|---|---|---|
| SQLCHAR * | CatalogName | Input | Catalog qualifier of a 3 part procedure name.
This must be a NULL pointer or a zero length string. |
| SQLCHAR * | ColumnName | Input | Buffer that might 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 or SchemaName. |
| SQLCHAR * | ProcName | Input | Buffer that might contain a pattern-value to qualify the result set by procedure name. |
| SQLCHAR * | SchemaName | Input | Buffer that might contain a pattern-value to
qualify the result set by schema name. For DB2 Universal Database™ for z/OS® and OS/390® 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. |
| SQLHSTMT | StatementHandle | Input | Statement handle. |
| SQLSMALLINT | NameLength1 | Input | Length of CatalogName. This must be set to 0. |
| SQLSMALLINT | NameLength2 | Input | Length of SchemaName. |
| SQLSMALLINT | NameLength3 | Input | Length of ProcName. |
| SQLSMALLINT | NameLength4 | Input | Length of ColumnName. |
DB2® UDB CLI returns information about the input, input and output, and output parameters associated with the stored procedure, but cannot return information about the descriptor 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 2 lists the columns in the result set. Applications should be aware that columns beyond the last column might be defined in future releases.
Because 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.
| Column number/name | Data type | Description |
|---|---|---|
| 1 PROCEDURE_CAT | VARCHAR(128) | The current server. |
| 2 PROCEDURE_SCHEM | VARCHAR(128) | The name of the schema containing PROCEDURE_NAME. |
| 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. |
| 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. |
| 10 DECIMAL_DIGITS | SMALLINT | The scale of the parameter. NULL is returned for data types where scale is not applicable. |
| 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 Database Management System (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 | VARCHAR(3) | 'NO' if the parameter does not accept NULL
values. 'YES' if the parameter accepts NULL values. |
| 13 REMARKS | VARCHAR(254) | Might contain descriptive information about the parameter. |
| 14 COLUMN_DEF | VARCHAR | The default value of the column. If NULL is 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 is 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 UDB CLI does not support interval data
types). For datetime data types, the SQL_DATA_TYPE field in the result set is SQL_DATETIME, and the SQL_DATETIME_SUB field returns 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 UDB 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.) |
| SQLSTATE | Description | Explanation |
|---|---|---|
| 24000 | Cursor state that is not valid | A cursor is already opened on the statement handle. |
| 40003 08S01 | Communication link failure | The communication link between the application and data source fails before the function is completed. |
| 42601 | PARMLIST syntax error | The PARMLIST value in the stored procedures catalog table contains a syntax error. |
| HY001 | Memory allocation failure | DB2 UDB CLI is unable to allocate memory required to support the processing or completion of the function. |
| HY008 | Operation canceled | |
| HY010 | Function sequence error | |
| HY014 | No more handles | DB2 UDB CLI is unable to allocate a handle due to internal resources. |
| HY021 | Internal descriptor that is not valid | The internal descriptor cannot be addressed or allocated, or it contains a value that is not valid. |
| HY090 | String or buffer length that is not valid | The value of one of the name length arguments is less than 0, but not equal SQL_NTS. |
| HYC00 | Driver not capable | DB2 UDB 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 |
SQLProcedureColumns() does not return information about the attributes of result sets that can 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() returns 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 */