Without an index, maintaining an autoincrement column becomes too expensive, that’s why MySQL requires an autoincrement column to be a leftmost part of an index. You should remove the autoincrement property before dropping the key: ALTER TABLE user_customer_permission MODIFY id INT NOT NULL; ALTER TABLE user_customer_permission DROP PRIMARY KEY; Note that you have a composite … Read more
select table_name, pg_relation_size(quote_ident(table_name)) from information_schema.tables where table_schema=”public” order by 2 This shows you the size of all tables in the schema public if you have multiple schemas, you might want to use: select table_schema, table_name, pg_relation_size(‘”‘||table_schema||'”.”‘||table_name||'”‘) from information_schema.tables order by 3 SQLFiddle example: http://sqlfiddle.com/#!15/13157/3 List of all object size functions in the manual.
SELECT * FROM users WHERE created >= CURDATE(); But I think you mean created < today You can compare datetime with date, for example: SELECT NOW() < CURDATE() gives 0, SELECT NOW() = CURDATE() gives 1.
A “Login” grants the principal entry into the SERVER. A “User” grants a login entry into a single DATABASE. One “Login” can be associated with many users (one per database). Each of the above objects can have permissions granted to it at its own level. See the following articles for an explanation of each Principals … Read more
No, you’ll have to use a workaround. If you must return a conditional bit 0/1 another way is to: SELECT CAST( CASE WHEN EXISTS(SELECT * FROM theTable where theColumn like ‘theValue%’) THEN 1 ELSE 0 END AS BIT) Or without the cast: SELECT CASE WHEN EXISTS( SELECT 1 FROM theTable WHERE theColumn LIKE ‘theValue%’ ) … Read more
Technically yes, but if a string makes sense to be the primary key then you should probably use it. This all depends on the size of the table you’re making it for and the length of the string that is going to be the primary key (longer strings == harder to compare). I wouldn’t necessarily … Read more
There are times that using OPTION(RECOMPILE) makes sense. In my experience the only time this is a viable option is when you are using dynamic SQL. Before you explore whether this makes sense in your situation I would recommend rebuilding your statistics. This can be done by running the following: EXEC sp_updatestats And then recreating … Read more
Neither of the highest voted answers are correct on SQL Server 2000. Perhaps they were using a different version. Here are the correct versions of both of them on SQL Server 2000. select t.range as [score range], count(*) as [number of occurences] from ( select case when score between 0 and 9 then ‘ 0- … Read more
As of MySQL 5.6.5, you can use the DATETIME type with a dynamic default value: CREATE TABLE foo ( creation_time DATETIME DEFAULT CURRENT_TIMESTAMP, modification_time DATETIME ON UPDATE CURRENT_TIMESTAMP ) Or even combine both rules: modification_time DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP Reference: http://dev.mysql.com/doc/refman/5.7/en/timestamp-initialization.html http://optimize-this.blogspot.com/2012/04/datetime-default-now-finally-available.html Prior to 5.6.5, you need to use the TIMESTAMP data type, … Read more
I know this is an old thread, but I just stumbled upon it and I feel this has not been explained completely. There is a huge difference in SQL*Plus between the meaning of a / and a ; because they work differently. The ; ends a SQL statement, whereas the / executes whatever is in … Read more