INSERT INTO tb1 (title,Family,Complexity)
Select o.title,o.Family,o.Complexity from tb2 o
ON DUPLICATE KEY UPDATE
title = CASE WHEN title <> o.title THEN o.title ELSE title END,
Family = CASE WHEN Family <> o.Family THEN o.Family ELSE Family END,
Complexity = CASE WHEN Complexity <> o.Complexity THEN o.Complexity ELSE Complexity END ;
I am trying to update tb1 with the records in tb2, ONLY if the records do not match up, as I am using an after update trigger in another table.
However when trying to execute this, I get an error "Column 'title' in field list is ambiguous".
I have been unable to solve this. Please assist
Try with full table name
INSERT INTO tb1 (title,Family,Complexity)
Select o.title,o.Family,o.Complexity from tb2 o
ON DUPLICATE KEY UPDATE
tb1.title = CASE WHEN tb1.title <> o.title THEN o.title ELSE tb1.title END,
tb1.Family = CASE WHEN tb1.Family <> o.Family THEN o.Family ELSE tb1.Family END,
tb1.Complexity = CASE WHEN tb1.Complexity <> o.Complexity THEN o.Complexity ELSE tb1.Complexity END ;
This is because the title field exists in multiple tables/references.
You should prefix your title with the table name or it's reference.
I like to replace a 'NULL' value in FG_NFG_Selektion column but only in those row where Plant='935S'
Tried:
UPDATE [Table] SET [FG_NFG_Selektion] = REPLACE([FG_NFG_Selektion], 'NULL', 'FG') WHERE [Plant] = '935S'
Message back: 10000 rows affected but still the same 'NULL' is there in the table.
Try with following query
UPDATE [Table] SET `FG_NFG_Selektion` = 'FG' WHERE `Plant` = '935S' AND `FG_NFG_Selektion` IS NULL;
I am trying to understand how to UPDATE multiple rows with different values and I just don't get it. The solution is everywhere but to me it looks difficult to understand.
For instance, three updates into 1 query:
UPDATE table_users
SET cod_user = '622057'
, date = '12082014'
WHERE user_rol = 'student'
AND cod_office = '17389551';
UPDATE table_users
SET cod_user = '2913659'
, date = '12082014'
WHERE user_rol = 'assistant'
AND cod_office = '17389551';
UPDATE table_users
SET cod_user = '6160230'
, date = '12082014'
WHERE user_rol = 'admin'
AND cod_office = '17389551';
I read an example, but I really don't understand how to make the query. i.e:
UPDATE table_to_update
SET cod_user= IF(cod_office = '17389551','622057','2913659','6160230')
,date = IF(cod_office = '17389551','12082014')
WHERE ?? IN (??) ;
I'm not entirely clear how to do the query if there are multiple condition in the WHERE and in the IF condition..any ideas?
You can do it this way:
UPDATE table_users
SET cod_user = (case when user_role = 'student' then '622057'
when user_role = 'assistant' then '2913659'
when user_role = 'admin' then '6160230'
end),
date = '12082014'
WHERE user_role in ('student', 'assistant', 'admin') AND
cod_office = '17389551';
I don't understand your date format. Dates should be stored in the database using native date and time types.
MySQL allows a more readable way to combine multiple updates into a single query. This seems to better fit the scenario you describe, is much easier to read, and avoids those difficult-to-untangle multiple conditions.
INSERT INTO table_users (cod_user, date, user_rol, cod_office)
VALUES
('622057', '12082014', 'student', '17389551'),
('2913659', '12082014', 'assistant','17389551'),
('6160230', '12082014', 'admin', '17389551')
ON DUPLICATE KEY UPDATE
cod_user=VALUES(cod_user), date=VALUES(date)
This assumes that the user_rol, cod_office combination is a primary key. If only one of these is the primary key, then add the other field to the UPDATE list.
If neither of them is a primary key (that seems unlikely) then this approach will always create new records - probably not what is wanted.
However, this approach makes prepared statements easier to build and more concise.
UPDATE table_name
SET cod_user =
CASE
WHEN user_rol = 'student' THEN '622057'
WHEN user_rol = 'assistant' THEN '2913659'
WHEN user_rol = 'admin' THEN '6160230'
END, date = '12082014'
WHERE user_rol IN ('student','assistant','admin')
AND cod_office = '17389551';
You can use a CASE statement to handle multiple if/then scenarios:
UPDATE table_to_update
SET cod_user= CASE WHEN user_rol = 'student' THEN '622057'
WHEN user_rol = 'assistant' THEN '2913659'
WHEN user_rol = 'admin' THEN '6160230'
END
,date = '12082014'
WHERE user_rol IN ('student','assistant','admin')
AND cod_office = '17389551';
To Extend on #Trevedhek answer,
In case the update has to be done with non-unique keys, 4 queries will be need
NOTE: This is not transaction-safe
This can be done using a temp table.
Step 1: Create a temp table keys and the columns you want to update
CREATE TEMPORARY TABLE temp_table_users
(
cod_user varchar(50)
, date varchar(50)
, user_rol varchar(50)
, cod_office varchar(50)
) ENGINE=MEMORY
Step 2: Insert the values into the temp table
Step 3: Update the original table
UPDATE table_users t1
JOIN temp_table_users tt1 using(user_rol,cod_office)
SET
t1.cod_office = tt1.cod_office
t1.date = tt1.date
Step 4: Drop the temp table
In php, you use multi_query method of mysqli instance.
$sql = "SELECT COUNT(*) AS _num FROM test;
INSERT INTO test(id) VALUES (1);
SELECT COUNT(*) AS _num FROM test; ";
$mysqli->multi_query($sql);
comparing result to transaction, insert, case methods in update 30,000 raw.
Transaction: 5.5194580554962
Insert: 0.20669293403625
Case: 16.474853992462
Multi: 0.0412278175354
As you can see, multiple statements query is more efficient than the highest answer.
Just in case if you get error message like this:
PHP Warning: Error while sending SET_OPTION packet
You may need to increase the max_allowed_packet in mysql config file.
UPDATE Table1 SET col1= col2 FROM (SELECT col2, col3 FROM Table2) as newTbl WHERE col4= col3
Here col4 & col1 are in Table1. col2 & col3 are in Table2 I Am trying to update each col1 where col4 = col3 different value for each row
I did it this way:
<update id="updateSettings" parameterType="PushSettings">
<foreach collection="settings" item="setting">
UPDATE push_setting SET status = #{setting.status}
WHERE type = #{setting.type} AND user_id = #{userId};
</foreach>
</update>
where PushSettings is
public class PushSettings {
private List<PushSetting> settings;
private String userId;
}
it works fine
I have a database table and What I required to do is that,
I need to update the column with the column name 'Co15' of every rows according to the following conditions
Co15 = SAMPLE if Co13 = 'c1' AND Col2 = 'b4'
Co15 = LIST if Co13 = 'c6'
Currently I am running each update query separately as follows
UPDATE tblname SET Co15 = 'SAMPLE' WHERE Co13 = 'c1' AND Col2 = 'b4';
UPDATE tblname SET Co15 = 'LIST' WHERE Co13 = 'c6';
But wanted to know if there is any way where I could run only one update query all at once.
Thanks
Try this
UPDATE tblname SET Co15=
CASE
WHEN Co13 = 'c1' AND Col2='b4' THEN 'SAMPLE'
WHEN Co13 = 'c6' THEN 'LIST'
END
exactly getting the output to as following as:
UPDATE tblname
SET col5= CASE
WHEN col3 = 'c1' AND col2 = 'b4' THEN 'SAMPL'
WHEN col3 = 'c6' THEN 'LIST'
END
example: sqlfiddle to click here
I got the following query :
INSERT INTO contracts_settings (contract_id, setting_id, setting_value)
VALUES (:contract_id, (
SELECT setting_id
FROM settings
WHERE setting_type = :setting_type
AND setting_name = :setting_name
LIMIT 1
), :setting_value)
ON DUPLICATE KEY UPDATE setting_value = :setting_value
The value with the prefix : is replaced with data using PHP PDO::bindBalue.
If the inner query find nothing (it return NULL) but also INSERT a NULL statement. How to avoid that ?
Thanks.
Convert the INSERT ... VALUES syntax to INSERT ... SELECT:
INSERT INTO contracts_settings
(contract_id, setting_id, setting_value)
SELECT
:contract_id,
setting_id,
:setting_value
FROM settings
WHERE setting_type = :setting_type
AND setting_name = :setting_name
LIMIT 1
ON DUPLICATE KEY UPDATE
setting_value = :setting_value ;