EXECUTE IMMEDIATE Statement

Native dynamic SQL uses the EXECUTE IMMEDIATE statement to process most dynamic SQL statements.

Caution:

When using dynamic SQL, beware of SQL injection, a security risk. For more information about SQL injection, see "SQL Injection".

Topics

Syntax

execute_immediate_statement ::=

Description of the illustration execute_immediate_statement.eps

(bulk_collect_into_clause ::=, dynamic_returning_clause ::=, into_clause ::=)

using_clause ::=

Description of the illustration using_clause.eps

Semantics

execute_immediate_statement

dynamic_sql_stmt

String literal, string variable, or string expression that represents a SQL statement. Its type must be either CHAR, VARCHAR2, or CLOB.

Note:

If dynamic_sql_statement is a SELECT statement, and you omit both into_clause and bulk_collect_into_clause, then execute_immediate_statement never executes.

For example, this statement never increments the sequence:

EXECUTE IMMEDIATE 'SELECT S.NEXTVAL FROM DUAL'

into_clause

Specifies the variables or record in which to store the column values that the statement returns. For more information about this clause, see "RETURNING INTO Clause".

Restriction on into_clause

Use if and only if dynamic_sql_stmt returns a single row.

bulk_collect_into_clause

Specifies one or more collections in which to store the rows that the statement returns. For more information about this clause, see "RETURNING INTO Clause".

Restriction on bulk_collect_into_clause

Use if and only if dynamic_sql_stmt can return multiple rows.

dynamic_returning_clause

Returns the column values of the rows affected by the dynamic SQL statement, in either individual variables or records. For more information about this clause, see "RETURNING INTO Clause".

Restriction on dynamic_returning_clause

Use if and only if dynamic_sql_stmt has a RETURNING INTO clause.

using_clause

Specifies bind variables, using positional notation.

Note:

If you repeat placeholder names in dynamic_sql_statement, be aware that the way placeholders are associated with bind variables depends on the kind of dynamic SQL statement. For details, see "Repeated Placeholder Names in Dynamic SQL Statements."

Restrictions on using_clause

Use if and only if dynamic_sql_stmt includes placeholders for bind variables.
If dynamic_sql_stmt has a RETURNING INTO clause (static_returning_clause), then using_clause can contain only IN bind variables. The bind variables in the RETURNING INTO clause are OUT bind variables by definition.

IN, OUT, IN OUT

Parameter modes of bind variables. An IN bind variable passes its value to dynamic_sql_stmt. An OUT bind variable stores a value that dynamic_sql_stmt returns. An IN OUT bind variable passes its initial value to dynamic_sql_stmt and stores a value that dynamic_sql_stmt returns. Default: IN.

For DML a statement with a RETURNING clause, you can place OUT bind variables in the RETURNING INTO clause without specifying the parameter mode, which is always OUT.

bind_argument

An expression whose value replaces its corresponding placeholder in dynamic_sql_stmt at run time.

Every placeholder in dynamic_sql_stmt must be associated with a bind_argument in the USING clause or RETURNING INTO clause (or both) or with a define variable in the INTO clause.

You can run dynamic_sql_stmt repeatedly using different values for the bind variables. You incur some overhead, because EXECUTE IMMEDIATE prepares the dynamic string before every execution.

Note:

Bind variables can be evaluated in any order. If a program determines order of evaluation, then at the point where the program does so, its behavior is undefined.

Restrictions on bind_argument

bind_argument cannot be an associative array indexed by string.
bind_argument cannot be the reserved word NULL.

To pass the value NULL to the dynamic SQL statement, use an uninitialized variable where you want to use NULL, as in Example 8-7.

Examples

Example 8-1, "Invoking Subprogram from Dynamic PL/SQL Block"
Example 8-7, "Uninitialized Variable Represents NULL in USING Clause"
Example 8-10, "Repeated Placeholder Names in Dynamic PL/SQL Block"