table1: id, field1(integer), field2, ...
as shown above field1 is integer that is serialized from 1 to 100
I enter a new record where field1 value is 45 from php form. given that this value already exists in the table (from 1 to 100)
**I want the query to store the new record Before the existing one in the table and increment field1 values starting from the second 45 **
Thanks much for help!
I would recommend against this. Normally, you should just insert rows in any order. If you want to sort, you probably will sort by a name, or by a relevant value.
If you want for some reason to have a particular sort order, then you can do it in two update statements:
1: Shift all the rows to make room for the new row.
UPDATE YourTable SET Field1 = Field1 + 1 WHERE Field1 >= 45
2: Insert the new row.
INSERT INTO YourTable (Field1) VALUES (45)
As you can tell, this can become inefficient, since you are actually updating all rows. If your table becomes larger, it will take more time to insert rows, especially at the beginning.
If you need you can optimize this a little, for instance, by keeping gaps between the rows. If you have a numbering in steps of 100, you can just insert the row at 4450, right between 4400 and 4500. You only need to renumber when there is no gap between the records where you want to insert the new row.
you need to run 2 sql like wise
$input_value = "45";
$sql1 = "UPDATE table1 SET field1=field1+1 WHERE field1>='$input_value' ";
$sql2 = "INSERT INTO table1 (field1, field2, ....) VALUES('$input_value', '$field2_value', ...); ";
Related
Currently, I find it time consuming to copy specific columns and values from Table 1 and paste the values onto Table 2 manually.
I have two tables ( In the same database ) like this:
How can I save time by doing the following? -
Grab specific ID from Table 1, in this case 1 and 2.
and copy just the Pcode & Desc values onto Table 2?
This is the end result I want to achieve (screenshot below)
The ID will be new, because its a new record. So technically I am updating Table 2 with new values that I have copied from Table 1
Every column is varchar type column expect the Id's
Also, I am using MySql Workbench.
This should do the trick;
INSERT INTO table2 (PCode, Desc)
SELECT Pcode, Desc
FROM table1
WHERE table1.id = 1 or table1.id = 2
First we start with empty table
rows = 0
Second we insert random rows let say 3400
rows = 3400
For the third time i count how many rows are in the table, then insert the new rows and after that delete rows <= from the count.
This logic only work for the first time. If that repeat the count will always be 3400 but the id will increase so it will not delete the rows
I cant use last inserted ID since the rows are random and I dont how many it will load.
// Update
"SELECT count(*) from table" - the total count so far
"INSERT INTO tab_videos_watched (id , name) values (id , name)" - this is random can be 3400 or 5060 or 1200
"DELETE FROM table WHERE idtable <= $table_count"
If id is auto incremented, then you should use like:
select max(id) from my_table;
Read this maxId into a variable and then use when issued a delete query like:
delete from my_table where id <= ?;
Replace query parameter with the last found maxId value.
Alternatively you can define a column last_inserted as datetime type.
Before next insertions, select it into a local variable.
select max(last_inserted) as 'last_inserted' from my_table;
And after insertions are made, use the last_inserted to delete records.
delete from my_table where last_inserted <= ?;
Replace query parameter with the last found last_inserted value.
I have this Statement:
INSERT INTO qa_costpriceslog (item_code, invoice_code, item_costprice)
VALUES (1, 2, (SELECT item_costprice FROM qa_items WHERE item_code = 1));
I'm trying to insert a value copy the same data of item_costprice, but show me the error:
Error Code: 1136. Column count doesn't match value count at row 1
How i can solve this?
Use numeric literals with aliases inside a SELECT statement. No () are necessary around the SELECT component.
INSERT INTO qa_costpriceslog (item_code, invoice_code, item_costprice)
SELECT
/* Literal number values with column aliases */
1 AS item_code,
2 AS invoice_code,
item_costprice
FROM qa_items
WHERE item_code = 1;
Note that in context of an INSERT INTO...SELECT, the aliases are not actually necessary and you can just SELECT 1, 2, item_costprice, but in a normal SELECT you'll need the aliases to access the columns returned.
You can just simply e.g.
INSERT INTO modulesToSections (fk_moduleId, fk_sectionId, `order`) VALUES
((SELECT id FROM modules WHERE title="Top bar"),0,-100);
I was disappointed at the "all or nothing" answers. I needed (again) to INSERT some data and SELECT an id from an existing table.
INSERT INTO table1 (id_table2, name) VALUES ((SELECT id FROM table2 LIMIT 1), 'Example');
The sub-select on an INSERT query should use parenthesis in addition to the comma as deliminators.
For those having trouble with using a SELECT within an INSERT I recommend testing your SELECT independently first and ensuring that the correct number of columns match for both queries.
Your insert statement contains too many columns on the left-hand side or not enough columns on the right hand side. The part before the VALUES has 7 columns listed, but the second part after VALUES only has 3 columns returned: 1, 2, then the sub-query only returns 1 column.
EDIT: Well, it did before someone modified the query....
As a sidenote to the good answer of Michael Berkowski:
You can also dynamically add fields (or have them prepared if you're working with php skripts) like so:
INSERT INTO table_a(col1, col2, col3)
SELECT
col1,
col2,
CURRENT_TIMESTAMP()
FROM table_B
WHERE b.col1 = a.col1;
If you need to transfer without adding new data, you can use NULL as a placeholder.
If you have multiple string values you want to add, you can put them into a temporary table and then cross join it with the value you want.
-- Create temp table
CREATE TEMPORARY TABLE NewStrings (
NewString VARCHAR(50)
);
-- Populate temp table
INSERT INTO NewStrings (NewString) VALUES ('Hello'), ('World'), ('Hi');
-- Insert desired rows into permanent table
INSERT INTO PermanentTable (OtherID, NewString)
WITH OtherSelect AS (
SELECT OtherID AS OtherID FROM OtherTable WHERE OtherName = 'Other Name'
)
SELECT os.OtherID, ns.NewString
FROM OtherSelect os, NewStrings ns;
This way, you only have to define the strings in one place, and you only have to do the query in one place. If you used subqueries like I initially did and like Elendurwen and John suggest, you have to type the subquery into every row. But using temporary tables and a CTE in this way, you can write the query only once.
I'm not really familiar with MySQL. But for performance reasons i want to avoid checking if a row already exists. Currently I've got a table with 2 columns (num, count) and I do something like this:
SELECT num FROM numbers WHERE num = 123
then if row exists...
UPDATE numbers SET count = count + 456 WHERE num = 123
else if row not exists...
INSERT INTO numbers (num, count) VALUES (123, 456)
Is there a possibility to avoid always querying the table. Something like a trigger... In the end, i just want to make an UPDATE, so that insertion is done automatically. thanks in advance
You don't need to use triggers, all you have to do is add UNIQUE constraint to your num column and then:
INSERT INTO numbers SET num = 123, count = 456 ON DUPLICATE KEY UPDATE count = count + 1;
Also, don't use reserved words for column names such as COUNT.
I want to do all these update in one statement.
update table set ts=ts_1 where id=1
update table set ts=ts_2 where id=2
...
update table set ts=ts_n where id=n
Is it?
Use this:
UPDATE `table` SET `ts`=CONCAT('ts_', `id`);
Yes you can but that would require a table (if only virtual/temporary), where you's store the id + ts value pairs, and then run an UPDATE with the FROM syntax.
Assuming tmpList is a table with an id and a ts_value column, filled with the pairs of id value, ts value you wish to apply.
UPDATE table, tmpList
SET table.ts = tmpList.ts_value
WHERE table.id = tmpList.id
-- AND table.id IN (1, 2, 3, .. n)
-- above "AND" is only needed if somehow you wish to limit it, i.e
-- if tmpTbl has more idsthan you wish to update
A possibly table-less (but similar) approach would involve a CASE statement, as in:
UPDATE table
SET ts = CASE id
WHEN 1 THEN 'ts_1'
WHEN 2 THEN 'ts_2'
-- ..
WHEN n THEN 'ts_n'
END
WHERE id in (1, 2, ... n) -- here this is necessary I believe
Well, without knowing what data, I'm not sure whether the answer is yes or no.
It certainly is possible to update multiple rows at once:
update table table1 set field1='value' where field2='bar'
This will update every row in table2 whose field2 value is 'bar'.
update table1 set field1='value' where field2 in (1, 2, 3, 4)
This will update every row in the table whose field2 value is 1, 2, 3 or 4.
update table1 set field1='value' where field2 > 5
This will update every row in the table whose field2 value is greater than 5.
update table1 set field1=concat('value', id)
This will update every row in the table, setting the field1 value to 'value' plus the value of that row's id field.
You could do it with a case statement, but it wouldn't be pretty:
UPDATE table
SET ts = CASE id WHEN 1 THEN ts_1 WHEN 2 THEN ts_2 ... WHEN n THEN ts_n END
I think that you should expand the context of the problem. Why do you want/need all the updates to be done in one statement? What benefit does that give you? Perhaps there's another way to get that benefit.
Presumably you are interacting with sql via some code, so certainly you can simply make sure that the three updates all happen atomically by creating a function that performs all three of the updates.
e.g. pseudocode:
function update_all_three(val){
// all the updates in one function
}
The difference between a single function update and some kind of update that performs multiple updates at once is probably not a very useful distinction.
generate the statements:
select concat('update table set ts = ts_', id, ' where id = ', id, '; ')
from table
or generate the case conditions, then connect it to your update statement:
select concat('when ', id, ' then ts_', id) from table
You can use INSERT ... ON DUPLICATE KEY UPDATE. See this quesion: Multiple Updates in MySQL
ts_1, ts_2, ts_3, etc. are different fields on the same table? There's no way to do that with a single statement.