CODEWITHSUNDEEP
mysqlsqldb2
Abruzzo Forte e Gentile
Abruzzo Forte e Gentile

Reputation: 14859

db2 equivalent of MySql REPLACE INTO

I very useful statement I like of MySql is REPLACE INTO table that is 'REPLACE a value if-exist OR INSERT INTO table If-Not-Exist'.

The documentation of db2 REPLACE is for a function operating on strings only so not with that meaning.

Is there any equivalent in db2? Right now I am looking also for keywords IF EXSTS/IF NOT EXIST.

Upvotes: 4

Views: 3182

Answers (2)

bhamby
bhamby

Reputation: 15440

DB2 uses the SQL standard MERGE statement to do basically the same thing. The syntax is different:

MERGE INTO table_to_upsert AS tab
USING (VALUES
        (1, 2, 3),
        (4, 5, 6),
        (7, 8, 9)
        -- more rows
    ) AS merge (C1, C2, C3)
    ON tab.key_to_match = merge.key_to_match
    WHEN MATCHED THEN
        UPDATE SET tab.C1 = merge.C1,
                   tab.C2 = merge.C2,
                   tab.C3 = merge.C3
    WHEN NOT MATCHED THEN
        INSERT (C1, C2, C3)
        VALUES (merge.C1, merge.C2, merge.C3)

Upvotes: 6

Ryan Goltry
Ryan Goltry

Reputation: 106

The DB2 function that you are looking for is MERGE

CREATE TABLE FOO ( ID INT, TITLE VARCHAR(500), VALUE );
CREATE TABLE BAR ( ID INT, TITLE VARCHAR(500), VALUE );
INSERT INTO FOO VALUES (1, 'BAR', 5.0);
INSERT INTO BAR VALUES (1, 'CCC', 3.0);
INSERT INTO BAR VALUES (2, 'DDD', 1.0);

MERGE INTO FOO AS F
   USING BAR AS B
   ON (F.ID = B.ID) WHEN MATCHED THEN UPDATE SET TITLE = B.TITLE, VALUE = F.VALUE - B.VALUE
   WHEN NOT MATCHED THEN INSERT VALUES(B.ID, B.TITLE, B.VALUE);

SELECT ID, TITLE, VALUE FROM FOO;
1    CCC    2.0
2    DDD    1.0

This explanation from DeveloperWorks will fill in some of the gaps.

Upvotes: 3

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