Purpose
Performs a macro.
For information about the embedded SQL EXEC statement, which is used to run macros from embedded SQL applications, see Teradata Vantage™ SQL Stored Procedures and Embedded SQL , B035-1148 .
Required Privileges
You must have EXECUTE privilege on the macro. The creator or any owner of the macro can grant the EXECUTE privilege to another. In addition, the immediate owner of the macro (the database in which the macro resides) must have the necessary privileges on objects named in the request set that are contained in the macro.
For more information, see Teradata Vantage™ SQL Data Definition Language Detailed Topics , B035-1184 and Teradata Vantage™ - Database Administration, B035-1093.
Syntax
Syntax Elements
- macro_name
- Name of the macro that is to be executed.
- constant_expression
- Constant or an expression involving constants that specifies a parameter value.
- parameter_name = constant_expression
- Parameter name as defined in the CREATE MACRO request, and supplies the value for that parameter.
ANSI Compliance
EXECUTE is a Teradata extension to the ANSI SQL:2011 standard.
Recommendation
A data definition request in a macro is not fully resolved until the macro is submitted for execution. Unqualified references to database objects are resolved at that time using the default database of the executing user.
Because of this, object references in data definition statements should always be fully qualified (as databasename.tablename) in the body of the macro.
Rules for Performing Macros
- The number of commas must match the macro definition if you do not use the parameter_name syntax.
- Any value in the EXECUTE constant expression list form without a specified parameter name can be a constant or an expression involving constants. In this context, DATE, TIME, and USER are considered constants.
- If an error message is returned when a macro is executed, it can be caused by an SQL request in the macro.
- The number of parameters used in the calling sequence must be equal to the number of parameters defined.
- When, for example, two parameters are defined and used, if they are both null, the following requests are all valid unless defaults are specified in the macro definition:
EXECUTE macro_1 '(, 1); EXECUTE macro_1 (,); EXECUTE macro_1 (NULL, NULL);
Access Logging and Errors
Any syntactic or semantic error identified and reported by the SQL parser results in an error being returned to you without logging the request.
Example: Named Parameter List
This request uses a named parameter list to execute macro new_emp1. See “CREATE MACRO” in Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144. Named parameters can be listed in any order.
EXECUTE new_emp1(number=10015, dept=500, name='Omura H', sex='M', position='Programmer');
The row for new employee Omura is inserted in the employee table.
Example: Positional Parameter List
This example uses a positional parameter list to execute macro new_emp2. See “CREATE MACRO” in Teradata Vantage™ SQL Data Definition Language Syntax and Examples, B035-1144. Note that a value is not specified for the dept parameter, which has a macro-defined default value. A comma is entered in the dept position to maintain the integrity of the positional sequence.
EXECUTE new_emp2 (10021, 'Smith T', , 'Manager', 'F', 'May 8, 1959', 16);
Example: Automatically Inserted Value
When the following request is processed, the default value for the dept parameter (900) is inserted automatically. The row for new employee Smith is added to the employee table, and then the department table is updated by incrementing the value for Department 900 in the emp_count column. The request uses a named parameter list to execute a macro named new_hire. Note that the value of the DOH (Date of Hire) column is an expression involving the DATE constant.
EXECUTE new_hire (fl_name='Toby Smith', title='Programmer', doh=DATE -1);
Example: Invoking an SQL UDF as an Argument to Macro Execution
The following example invokes the SQL UDF value_expression as an argument to the macro m1.
EXECUTE m1 (test.value_expression(1,2), 2, 3);