SQLDescribeParam
SQLDescribeParam is an ODBC API which returns metadata for the parameters of a query.
In earlier releases of the HCL
OneDB™ ODBC Driver, the SQLDescribeParam API
returned SQL_UNKNOWN if the API was called to get information about
an expression value or a parameter that was embedded inside another
routine. This restriction no longer applies to values of BOOLEAN,
LVARCHAR, or of built-in non-opaque HCL
OneDB data
types that are returned by the following expressions in other UDRs:
- Binary arithmetic expressions
- Addition ( + )
- Subtraction ( - )
- Multiplication ( * )
- Division ( / )
- Relational operator expressions
- Less than ( < )
- Less than or equal to ( <= )
- Equal to ( =, == )
- Greater than or equal to ( >= )
- Greater than ( > )
- Not equal to ( <>, != )
- The following string operations
- Concatenation ( || )
- MATCHES
- LIKE
- BETWEEN ... AND conditional expressions
For example, if the column tab1.c1 is an INT data
type, SQLDescribeParam() returns type int for the
input host variable of the following query:
select c1, c2 from tab1 where ABS(c1) > ?;
The UDR from the other side of the expression can be a
column expression or a built-in routine, but it cannot be a user-defined
routine. In earlier releases, the SQLDescribeParam API
returns SQL_UNKNOWN for expression values and parameters that are
embedded in another procedure in the following cases:
- The value on the other side of the expression is a user-defined routine.
- Another operand of the same expression is a user-defined routine.
- The data type of any operand of the expression is not a BOOLEAN, LVARCHAR, or a built-in non-opaque data type.