my sql using insert and select together - mysql

Im trying to use insert and select in one query.Both the tables have same number of columns except for one column in the table where data is to be inserted
table2 is the mirror image of table1 except for a column called comments;
insert into table2 select * from table1 where city='XYZ' and name = 'STY'
since the no of columns arent equal i get the following error:
Column count doesn't match value count at row 1

INSERT INTO table2 (Coln1,Coln2,Coln3,....) SELECT * FROM table1 WHERE `city`='XYZ' AND `name`='STY';
For the extra column in the table2, NULL is set by default.

Related

Fill Column of SQL Table

I'm trying to fill a certain column of a SQL table with data from another table. I have a column named "size" in my table which should return the number of rows in the 2nd table where the id of both rows is the same. Is there a way to populate a SQL column based on a certain command? I would love to be able to fill the column based on this command:
SELECT count(*)
FROM second_table
WHERE id = "row_id";
Here is a sample database with the two tables:
Table 1
Name
id
tiger
1
lion
2
gazelle
1
Here is the desired output for Table 2:
id
Number of Animals
1
2
2
1
I am trying to fill the Number of Animals column but do it automatically and dynamically when another row is added or deleted to Table 1, which is why I want the Select count(*) SQL statement as the code for the column.
One method is a correlated subquery:
update table1 t1
set size = (select count(*)
from table2 t2
where t2.id = t1.id
);
If you need to do this dynamically (as data is inserted), then you would need to use a trigger. However, I would suggest that you calculate the value as needed, unless there is a specific reason why you need to store it.
I guess you need something like this:
CREATE TRIGGER UpdateAnimalCountTable2
AFTER INSERT ON `Table1` FOR EACH ROW
begin
DECLARE NewCount int;
SELECT count(1)
INTO #NewCount
FROM Table1
WHERE Table1.id= NEW.id;
UPDATE Table2
SET NoOfAnimals = #NewCount
WHERE id = NEW.id;
END;
Above is the trigger which will be executed after every insert in Table1 and will update the count in Table 2 for ID which just got inserted in Table1.

MYSQL Get id from Table1 and Insert to Table2 while INSERTING Values (USER Form)

I have 2 tables:
Table1
u_id email
1 user1#y.com
2 user2#h.com
and
Table2
id u_id values
had to insert values to table2 with u_id when user enters from form
Example:I need to add the value table1 u_id while that user is logged in into table2 that is id increments in table and u_id from table1 and values as user enters from table2
i tried something this query however not successful
insert into table2 (u_id,values)
values ((select u_id from table1), 'values')
The problem with your query is that the subquery returns multiple rows (one value per row in table1), while the database expects a scalar value.
I would expect that you know the email of the current user, and want to recover the corresponding u_id to insert a new row in table2, along with a literal value. If so, I would recommend the insert ... select syntax:
insert into table2 (u_id, val)
select u_id, 'foo' from table1 where email = 'user1#y.com'
Side note: values is a SQL keyword, hence not a good choice for a column name (you would need to quote this identifier every time you use it). I renamed this column to val in the query.

Insert records for each selected record

I have two tables, Table1 contains a list of records with columns super_id, user_name and job_type
Table2 contains a 3 columns as well super_id, view and time
Using a select query with criteria on table I would like to create one record per super_id in Table2
Meaning if the select query was SELECT super_id FROM Table1 WHERE job_type = “Instructor”
RF34323 through RF34328 would appear would each be inserted once into Table2 where the View column is always View1 and time is the current date.
How can an Select Insert query like this written?
The following is an example of the 2 tables:
Is this what you want?
insert into table2 (super_id, `view`, `time`)
select super_id, 'view1', now()
from table1
where job_type = 'Instructor';
Note that view and time are very BAD choices for column names, because they are keywords in SQL.
If you want to create table2, then use create table table2 as instead of insert.
Also, you can default the time column to the insertion time, if you set up the table properly.

Overwriting content from one table to existing table

I have two different tables with two colums that have the same name, datatype and size.
My issue:
When I try to copy the content from one column to the other,
update Table1
set Column4 = (select Column1 from Table2);
I get an error. (subquery returns more than one row)
My question:
Is there a way for me to copy the content from Table2 to Table1 in a similar fashion as the code shows above?
Use Insert ... Select
Insert INTO Table1 (Column4)
SELECT Column1 FROM Table2

Copy row from one MySQL DB to another

How it's possible to copy one entry row of a table with same data to another (same ID, same data values) Database -> same table?
Example:
Table Units:
UID Department Name Item
67 HR John Doe Table
If both tables equal no. of columns and in same order you want to insert then just use below simple query-
INSERT INTO mytable SELECT * FROM units WHERE uid=67;
If you want to insert selected column in another table's selected columns and in your order then use below-
INSERT INTO mytable(col1,col2,col3,col4) SELECT uid,department,`name`,item FROM units WHERE uid=67;
If I understand you correctly you want to copy some rows to table of another DB.
Try INSERT SELECT Query:
insert into db1.tbl(id,col1,col2)
select id,col1,col2 from db2.tbl;
Use trigger option in mysql to make new table with same data.
Suppose if you want to copy table1 data to table2 with some condition.
INSERT INTO table2 (ID, NAME) SELECT Col1, Col2 FROM table1 WHERE Col1='<Your_Condition>';
Here table2 have fields like ID and NAME and table1 have fields like Col1 and Col2.
In that case, above query copy table1 data to table2 on these fields where condition matched on table1, if you want to copy whole data of table1 then remove the WHERE condition from Select Query.