How do you insert selected rows from
table_target using SQL in MySQL where:
- Both tables have the same schema
- All columns should transfer except for the auto-increment
- Without explicitly writing all the column names, as that would be tedious
INSERT INTO table_target SELECT * FROM table_source fails on duplicate entries for primary key.
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Either you list all of the fields you want in the insert…select, or you use something else externally to build the list for you.
SQL does not have something like
SELECT * except somefield FROM, so you’ll have to bite the bullet and write out the field names.
Column names have to be specified –
INSERT INTO table_target SELECT NULL, column_name1, column_name2, column_name3, ... FROM table_source;
Just pass NULL as a value for the auto-increment id field.
Of course, primary key must be unique. It depends on what you want to achieve, but you could exclude rows with a primary key that already exists.
INSERT INTO table_target SELECT * FROM table_source WHERE table_source.id NOT IN (SELECT id FROM table_target)
UPDATE: since you also need the extra rows, you should resolve the conflict first, does table_source have relationships? If not you could change those keys:
UPDATE table_source SET id = id + 1000 WHERE id IN (SELECT id FROM table_target)
Where 1000, is a constant, big enough so they go after the end of your table.
Tedious but safe and correct.
Writing INSERT statements without providing a list of columns leads to code that’s hard to debug and, more importantly, very fragile code that will break if the definition of the table is changed.
If you absolutely can’t write the column names out yourself then it’s relatively easy to build a tool into your code that will create the comma-separated list for you.
This is my final solution to mass update with ‘replace insert’ command.
SET @@session.group_concat_max_len = @@global.max_allowed_packet; SET @schema_db = 'db'; SET @tabl = 'table'; SET @cols = (SELECT CONCAT('`',GROUP_CONCAT(COLUMN_NAME SEPARATOR '`, `'), '`') FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = @schema_db AND TABLE_NAME = @tabl GROUP BY TABLE_NAME); SET @Querystr = CONCAT('REPLACE INTO ',@schema_db,'.',@tabl,' SELECT ', @cols,' FROM import.tbl_', @tabl); PREPARE stmt FROM @Querystr; EXECUTE stmt;
I think you could use syntax like:
INSERT INTO table (a,b,c) VALUES (1,2,3) ON DUPLICATE KEY UPDATE c=c+1;
Hope it helps
INSERT IGNORE just “bypass” the duplicate rows.
You can probably do it with prepared statements.
PREPARE table_target_insert FROM 'INSERT INTO table_target SELECT ? FROM table_source'; SET @cols:=''; SELECT @cols:=GROUP_CONCAT(IF(column_name = 'id','NULL',column_name) separator ",") FROM information_schema.columns WHERE table_name='table_source'; EXECUTE table_target_insert USING @cols;
It seems as if columns can not be given as a place holder in a MySQL Prepared Statement. I have compiled the following solution for testing:
SET @schema_db = 'DB'; SET @table = 'table'; SET @cols = (SELECT CONCAT(GROUP_CONCAT(COLUMN_NAME SEPARATOR ', '), "n") FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = @schema_db AND TABLE_NAME = @table GROUP BY TABLE_NAME); SET @Querystr = CONCAT('SELECT',' ', @cols,' ','FROM',' ',@schema_db,'.',@table,' ', 'Limit 5'); PREPARE stmt FROM @Querystr; EXECUTE stmt;
You can use dynamic query:
DECLARE @Columns VARCHAR(MAX)='' DECLARE @Query VARCHAR(MAX)='' SELECT @Columns = ISNULL(@Columns +',', '') + T.COLUMN_NAME FROM ( select name as COLUMN_NAME from sys.all_columns where object_id = (select object_id from sys.tables where name = 'Source_Table') and is_identity = 0 )T set @Query = 'insert into Target_Table (' + SUBSTRING(@Columns,2 , 9999) + ') select ' + SUBSTRING(@Columns,2 , 9999) + ' from Source_Table'; PRINT @Query EXEC(@Query)
The easiest way to do it is to use phpmyadmin to write the list of columns, then to change it as needed, in the example below I want to duplicate row with id=1078 and in this table I have id unique auto increment and alias unique.therefore I created my query as follow, with id & alias replaced by a desired value. and it worked like a charm.
Alternatively, to auto increment id, use the following Join statement:
from (SELECT MAX(