SQLITE bulk UPDATE statement

9
votes

I want to perform many SQL UPDATE Statements like these:

UPDATE cityd SET time_zone='-7.000000' WHERE locId = 173567;
UPDATE cityd SET time_zone='-8.000000' WHERE locId = 173568;
UPDATE cityd SET time_zone='-6.000000' WHERE locId = 173569;
UPDATE cityd SET time_zone='-5.000000' WHERE locId = 173570;
UPDATE cityd SET time_zone='-6.000000' WHERE locId = 173571;

I want to optimize the transaction time, so I need to use BEGIN TRANSACTION/COMMIT pair. How to write this in SQL Syntax in SQLtite Manager?

Edit: When I use the standard syntax in SQLite Manager I receive this error message: "SQLiteManager: BEGIN TRANSACTION; [ cannot start a transaction within a transaction "

2
sqlsqlite
So the code that's running your SQL statements is already putting a transaction around them. Thus you don't need to wrap a transaction around them in this case… – Donal Fellows

2 Answers

19
votes

According on SQL Documention, there are two supported syntax of CASE

CASE x WHEN w1 THEN r1 WHEN w2 THEN r2 ELSE r3 END

CASE WHEN x = w1 THEN r1 WHEN x = w2 THEN r2 ELSE r3 END

So your multiple UPDATE statements can be further simplified into

UPDATE  cityd
SET     time_zone = CASE locId
                        WHEN 173567 THEN '-7.000000'
                        WHEN 173568 THEN '-8.000000'
                        WHEN 173569 THEN '-6.000000'
                        WHEN 173570 THEN '-5.000000'
                        WHEN 173571 THEN '-6.000000'
                    END
WHERE   locId IN (173567, 173568, 173569, 173570, 173571)
1
votes
BEGIN TRANSACTION;
.....YOUR SQL Statements here

COMMIT;