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How to add a primary key to a MySQL table?
...le as it is written now, which can be a little confusing when doing simple SELECT * ...
– StefanK
Apr 12 '19 at 6:45
H...
What's the difference between comma separated joins and join on syntax in MySQL? [duplicate]
...LL
)
Following query will give me all columns and rows from both tables
SELECT
*
FROM table1, table2
Following query will give me columns from first table with table alias called 'table2'
SELECT
*
FROM table1 table2
If you mistakenly forget comma in comma-separated join, second table...
How to find all tables that have foreign keys that reference particular table.column and have values
...
Here you go:
USE information_schema;
SELECT *
FROM
KEY_COLUMN_USAGE
WHERE
REFERENCED_TABLE_NAME = 'X'
AND REFERENCED_COLUMN_NAME = 'X_id';
If you have multiple databases with similar tables/column names you may also wish to limit your query to a particul...
MySQL - How to select data by string length
...
select LENGTH('Ö'); results 2!! András Szepesházi's answer is the correct one!
– fubo
Oct 24 '13 at 13:59
...
You can't specify target table for update in FROM clause
...llow you to write queries like this:
UPDATE myTable
SET myTable.A =
(
SELECT B
FROM myTable
INNER JOIN ...
)
That is, if you're doing an UPDATE/INSERT/DELETE on a table, you can't reference that table in an inner query (you can however reference a field from that outer table...)
Th...
How to find duplicates in 2 columns not 1
..._title for each row.
As far as finding the existing duplicates try this:
select stone_id,
upcharge_title,
count(*)
from your_table
group by stone_id,
upcharge_title
having count(*) > 1
...
Get current AUTO_INCREMENT value for any table
...'TableName' ;
You can get exactly this information by using this query:
SELECT `AUTO_INCREMENT`
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'DatabaseName'
AND TABLE_NAME = 'TableName';
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...
How to use GROUP BY to concatenate strings in MySQL?
...
SELECT id, GROUP_CONCAT(name SEPARATOR ' ') FROM table GROUP BY id;
http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
From the link above, GROUP_CONCAT: This function returns a string res...
Are table names in MySQL case sensitive?
Are table names in MySQL case sensitive?
5 Answers
5
...
Unknown Column In Where Clause
...om right to left. So the where clause is parsed and evaluate prior to the select clause. Because of this the aliasing of u_name to user_name has not yet occurred.
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