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Dynamic SQL
Oracle Database PL/SQL 10g Programming
Chapter 13
Dyanmic SQL
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2006
Defining Dynamic SQL
Working with Native Dynamic SQL
Working with DBMS_SQL Built-in
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 2
Dynamic SQL
Defining Dynamic SQL
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Build and run SQL statements on the fly.
Evaluates dependencies at runtime.
Defines column and table names at runtime.
Lets you define polymorphic statements.
Build dynamic SQL statements by using:
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2006
Native Dynamic SQL (NDS) uses EXECUTE IMMEDIATE to run
dynamic statements.
DBMS_SQL Built-in provides a collection of overloaded
functions and procedures to build and execute dynamic
queries.
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 3
Dynamic SQL
Native Dynamic SQL (NDS)
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2006
Enables dynamic DDL and DML SQL
statements without bind variables.
Enables dynamic DML with a known
list of bind variables.
Enables dynamic DQL.
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 4
Dynamic SQL
NDS Advantages
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2006
It performs faster than DBMS_SQL.
It has syntax that mirrors standard
SQL syntax.
It fetches directly into PL/SQL record
types.
It supports all PL/SQL data types,
including user-defined data types.
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 5
Dynamic SQL
NDS Advantages
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It supports bulk processing:
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2006
BULK FETCH statement
BULK EXECUTE IMMEDIATE statement
FORALL statement
COLLECT INTO clause
RETURNING INTO clause
%BULK_ROWCOUNT attribute
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 6
Dynamic SQL
NDS: EXECUTE IMMEDIATE Clauses
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INTO
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Mode is OUT only.
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Supports only single row return statements.
RETURNING <variable> INTO <bind_variable>
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Supports name positional notation assigning variables to bind
variables.
USING
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Modes are IN and OUT by itself.
Mode is IN only when concurrently using RETURNING
<variable> INTO <bind_variable> clause.
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Supports only positional
notation.
Oracle Database PL/SQL 10g Programming
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2006
Modes are IN and OUT.
(Chapter 13)
Page 7
Dynamic SQL
NDS: Without bind variables
DECLARE
retval
NUMBER;
statement
VARCHAR2(4000);
BEGIN
statement := 'CREATE SEQUENCE ' || a_sequence
|| 'INCREMENT BY 1';
EXECUTE IMMEDIATE statement;
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 8
Dynamic SQL
NDS: Without substitution variables
DECLARE
retval
NUMBER;
sequence_name VARCHAR2(30) := 'sequence_name';
statement
VARCHAR2(4000);
BEGIN
statement := 'CREATE SEQUENCE '||sequence_name||' '
|| 'INCREMENT BY 1';
EXECUTE IMMEDIATE statement;
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 9
Dynamic SQL
NDS: With bind variables
DECLARE
retval
NUMBER;
sequence_name VARCHAR2(30) := 'sequence_name';
statement
VARCHAR2(4000);
BEGIN
statement := 'CREATE SEQUENCE :sequence_name '
|| 'INCREMENT BY 1';
EXECUTE IMMEDIATE statement USING sequence_name;
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 10
Dynamic SQL
NDS: With bind output variables
DECLARE
column_table1 VARCHAR2_NESTED_TABLE;
column_table2 VARCHAR2_NESTED_TABLE;
BEGIN
statement := 'BEGIN '
|| 'SELECT
column_name1, column_name2 '
|| 'BULK COLLECT INTO :column_table '
|| 'FROM
table_name;'
|| 'END;';
EXECUTE IMMEDIATE statement
USING OUT column_table1, OUT column_table2;
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 11
Dynamic SQL
DBMS_SQL Built-in



2006
Enables dynamic DDL and DML SQL
statements without bind variables.
Enables dynamic DML with a known
list of bind variables.
Enables dynamic DQL.
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 12
Dynamic SQL
DBMS_SQL Built-in: Without bind variables
DECLARE
c
INTEGER := DBMS_SQL.OPEN_CURSOR;
fdbk
INTEGER;
statement
VARCHAR2(4000);
BEGIN
statement := 'CREATE SEQUENCE ' || a_sequence
|| 'INCREMENT BY 1';
DBMS_SQL.PARSE(c,statement,DBMS_SQL.NATIVE);
fdbk := DBMS_SQL.EXECUTE(c);
DBMS_SQL.CLOSE_CURSOR(c);
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 13
Dynamic SQL
DBMS_SQL Built-in: With bind variables
DECLARE
c
INTEGER := DBMS_SQL.OPEN_CURSOR;
fdbk
INTEGER;
input
VARCHAR2(30);
statement
VARCHAR2(4000);
BEGIN
statement := 'INSERT INTO a_table '
|| 'VALUES (:bind_variable)';
DBMS_SQL.PARSE(c,statement,DBMS_SQL.NATIVE);
DBMS_SQL.BIND_VALUE(c,bind_variable,input);
fdbk := DBMS_SQL.EXECUTE(c);
DBMS_SQL.CLOSE_CURSOR(c);
END;
/
Oracle Database PL/SQL 10g Programming
2006
(Chapter 13)
Page 14
Dynamic SQL
DBMS_SQL Built-in: With bind array variables
DECLARE
c
INTEGER := DBMS_SQL.OPEN_CURSOR;
fdbk
INTEGER;
input
VARCHAR2_NESTED_TABLE;
statement
VARCHAR2(4000);
BEGIN
statement := 'INSERT INTO a_table '
|| 'VALUES (:bind_variable)';
DBMS_SQL.PARSE(c,statement,DBMS_SQL.NATIVE);
DBMS_SQL.BIND_ARRAY(c,bind_variable,input);
fdbk := DBMS_SQL.EXECUTE(c);
DBMS_SQL.CLOSE_CURSOR(c);
END;
/
Oracle Database PL/SQL 10g Programming
2006
(Chapter 13)
Page 15
Dynamic SQL
DBMS_SQL Built-in: With output bind variables
DECLARE
c
INTEGER := DBMS_SQL.OPEN_CURSOR;
fdbk
INTEGER;
output
VARCHAR2(4000);
statement
VARCHAR2(4000);
BEGIN
statement := 'SELECT column_value FROM a_table';
DBMS_SQL.PARSE(c,statement,DBMS_SQL.NATIVE);
DBMS_SQL.DEFINE_COLUMN(c,1,output,4000);
… loop_on_next_page …
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 16
Dynamic SQL
DBMS_SQL Built-in: With output bind variables
DECLARE
… noted_on_prior_page …
BEGIN
LOOP
EXIT WHEN DBMS_SQL.FETCH_ROWS(c) = 0;
DBMS_SQL.COLUMN_VALUE(c,1,output);
DBMS_OUTPUT.PUT_LINE('Print ['||output||']');
END LOOP;
END;
/
2006
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 17
Summary
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2006
Defining Dynamic SQL
Working with Native Dynamic SQL
Working with DBMS_SQL Built-in
Oracle Database PL/SQL 10g Programming
(Chapter 13)
Page 18