Execute the SQL statement

After an SQL statement is prepared, the database server can execute it. The way to execute a prepared statement depends on:

How many rows (groups of values) the SQL statement returns:
- Statements that return one row of data include a singleton SELECT and an EXECUTE FUNCTION statement.
- Statements that can return more than one row of data require a cursor to execute; they include a non-singleton SELECT and an EXECUTE FUNCTION statement.
- All other SQL statements, including EXECUTE PROCEDURE, return no rows of data.
For more information about how to execute statements that require cursors, see A database cursor.
Whether the statement has input parameters
If so, the statement must be executed with the USING clause:
- For SELECT and INSERT statements, use the OPEN...USING statement.
- For non-SELECT statements, use the EXECUTE...USING statement.
Whether you know the data types of statement columns at compile time:
- When you know the number and data types of the columns at compile time, you can use host variables to hold the column values.
  For more information, see SQL statements that are known at compile time.
- When you do not know the number and data types of columns at compile time, you must use the DESCRIBE statement to define the column and a dynamic-management structure to hold the column values.
  For more information, see Determine SQL statements.

The following tables summarize how to execute the different types of prepared SQL statements.

Table 1. Executing prepared SQL statements that do not return rows (except INSERT, which is associated with a cursor)
Type of SQL statement	Input parameters	Statement to execute	See
With no input parameters	No	EXECUTE	Execute non-SELECT statements
When number and data types of input parameters are known	Yes	EXECUTE...USING	An EXECUTE USING statement
When number and data types of input parameters are not known	Yes	EXECUTE...USING SQL DESCRIPTOR EXECUTE...USING DESCRIPTOR	Handling a parameterized UPDATE or DELETE statement Handling a parameterized UPDATE or DELETE statement

Table 2. Executing an INSERT statement that is associated with a cursor
Type of SQL statement	Input parameters	Statement to execute	See
With no input parameters	No	OPEN	Declare a select cursor
When number and data types of input parameters (insert columns) are known	Yes	OPEN...USING	An OPEN USING statement, Handling an unknown column list
When number and data types of input parameters are not known	Yes	OPEN...USING SQL DESCRIPTOR OPEN...USING DESCRIPTOR	Handling an unknown column list Handling an unknown column list

Table 3. Executing prepared SQL statements that can return more than one row: non-singleton SELECT, SPL function
Type of SQL statement	Input parameters	Statement to execute	See
With no input parameters	No	OPEN	Declare a select cursor
When number and data types of select-list columns are not known	No	OPEN	Execute a SELECT that returns multiple rows, Execute a SELECT that returns multiple rows
When number and data types of return values are not known	No	OPEN	Executing a cursor function, Executing a cursor function
When number and data types of input parameters are known	Yes	OPEN...USING	An OPEN USING statement
When number and data types of input parameters are not known	Yes	OPEN...USING SQL DESCRIPTOR OPEN...USING DESCRIPTOR	Execute a parameterized SELECT that returns multiple rows Execute a parameterized SELECT that returns multiple rows

Table 4. Executing prepared SQL statements that return only one row: singleton SELECT, any external function, or an SPL function that returns only one group of values
Type of SQL statement	Input parameters	Statement to execute	See
With no input parameters	No	EXECUTE...INTO	The PREPARE and EXECUTE INTO statements
When number and data types of returned values are not known	No	EXECUTE...INTO DESCRIPTOR EXECUTE...INTO SQL DESCRIPTOR	Handling an unknown select list Execute a noncursor function Handling an unknown select list Execute a noncursor function
When number and data types of input parameters are known	Yes	EXECUTE...INTO ...USING	An EXECUTE USING statement
When number and data types of input parameters are not known	Yes	EXECUTE...INTO ...USING SQL DESCRIPTOR EXECUTE...INTO ...USING DESCRIPTOR	Execute a parameterized singleton SELECT statement Execute a parameterized singleton SELECT statement