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Expert Member
Insert when, Insert all when difference
Insert when syntax is
INSERT
WHEN condition THEN
INTO table_name column_list
VALUES (values_list)
WHEN condition THEN
INTO table_name (column_list)
VALUES (values_list)
ELSE
INTO table_name (column_list)
VALUES (values_list)
SELECT column_list FROM table_name;
Insert all when syntax is
INSERT ALL
WHEN (condition) THEN
INTO table_name (column_list)
VALUES (values_list)
WHEN (condition) THEN
INTO table_name (column_list)
VALUES (values_list)
ELSE
INTO table_name (column_list)
VALUES (values_list)
SELECT column_list FROM ;
What is the difference in their functionality?
Last edited by krishnaindia2007; 12-03-2007 at 11:01 PM.
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Expert Member
Re: Insert when, Insert all when difference
Insert All functionality
Multitable inserts allow a single INSERT INTO .. SELECT statement to conditionally, or non-conditionally, insert into multiple tables. This statement reduces table scans and PL/SQL code necessary for performing multiple conditional inserts compared to previous versions. It's main use is for the ETL process in data warehouses where it can be parallelized and/or convert non-relational data into a relational format:
-- Unconditional insert into ALL tables
INSERT ALL
INTO sal_history VALUES(empid,hiredate,sal)
INTO mgr_history VALUES(empid,mgr,sysdate)
SELECT employee_id EMPID, hire_date HIREDATE, salary SAL, manager_id MGR
FROM employees WHERE employee_id > 200;
-- Pivoting insert to split non-relational data
INSERT ALL
INTO Sales_info VALUES (employee_id,week_id,sales_MON)
INTO Sales_info VALUES (employee_id,week_id,sales_TUE)
INTO Sales_info VALUES (employee_id,week_id,sales_WED)
INTO Sales_info VALUES (employee_id,week_id,sales_THUR)
INTO Sales_info VALUES (employee_id,week_id, sales_FRI)
SELECT EMPLOYEE_ID, week_id, sales_MON, sales_TUE,
sales_WED, sales_THUR,sales_FRI
FROM Sales_source_data;
-- Conditionally insert into ALL tables
INSERT ALL
WHEN SAL>10000 THEN
INTO sal_history VALUES(EMPID,HIREDATE,SAL)
WHEN MGR>200 THEN
INTO mgr_history VALUES(EMPID,MGR,SYSDATE)
SELECT employee_id EMPID, hire_date HIREDATE, salary SAL, manager_id MGR
FROM employees WHERE employee_id > 200;
-- Insert into the FIRST table with a matching condition
INSERT FIRST
WHEN SAL > 25000 THEN
INTO special_sal VALUES(DEPTID,SAL)
WHEN HIREDATE like ('%00%') THEN
INTO hiredate_history_00 VALUES(DEPTID,HIREDATE)
WHEN HIREDATE like ('%99%') THEN
INTO hiredate_history_99 VALUES(DEPTID,HIREDATE)
ELSE
INTO hiredate_history VALUES(DEPTID, HIREDATE)
SELECT department_id DEPTID, SUM(salary) SAL,
MAX(hire_date) HIREDATE
FROM employees GROUP BY department_id;
The restrictions on multitable INSERTs are:
Multitable inserts can only be performed on tables, not on views or materialized views.
You cannot perform a multitable insert via a DB link.
You cannot perform multitable inserts into nested tables.
The sum of all the INTO columns cannot exceed 999.
Sequences cannot be used in the subquery of the multitable insert statement.
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