How to diagnose and fix the 22002 null_value_no_indicator_parameter error code in Postgres.

by

The 22002 error code in PostgreSQL, labeled as null_value_no_indicator_parameter, occurs when a NULL value is encountered in a context where an indicator parameter is required to process that NULL value but none is supplied. This situation can arise when using callable statements like stored procedures or functions that have output parameters.

To diagnose and fix the 22002 error code, you should:

  1. Check the stored procedure, function, or prepared statement that is being called to make sure it properly handles NULL values.
  2. Ensure that any host variables (in the case of a language like C or using an interface like ODBC) that might receive NULL values have an associated indicator variable to handle the possibility of a NULL value.

Here’s an example in the context of a language interface like ODBC, where you’d typically bind variables to SQL parameters and need to provide an indicator for possible NULL values:

SQLINTEGER indicator;
SQLINTEGER dataValue;

// Bind the variable to the parameter with an indicator
SQLBindParameter(hstmt, 1, SQL_PARAM_OUTPUT, SQL_C_SLONG, SQL_INTEGER, 0, 0, &dataValue, 0, &indicator);

// Execute the statement
SQLExecDirect(hstmt, (SQLCHAR*)"CALL your_procedure(?)", SQL_NTS);

// Check if the returned value is NULL
if (indicator == SQL_NULL_DATA) {
    // Handle NULL value
}

In this pseudo-code example, indicator is an integer used to indicate whether the dataValue is NULL or not after calling the procedure. If indicator is set to SQL_NULL_DATA, it indicates that the output is NULL.

When working directly within PostgreSQL using SQL, make sure that any function or procedure that might return NULL has a proper check in place to handle such cases. If you’re using a language interface, ensure you have a corresponding indicator variable.

For more specific guidance on the 22002 error code, refer to the PostgreSQL documentation, which provides detailed information on error codes and their meanings.

Leave a Comment