大约有 5,880 项符合查询结果（耗时：0.0166秒） [XML]
What's the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN? [duplicate]
... don't do it for me. Why is the top right picture not simply SELECT * FROM TableA;? Why is the top left picture not simply SELECT * FROM TableB;? Why is the top middle picture not SELECT * FROM A INTERSECT SELECT * FROM B ? etc
– onedaywhen
Sep 9 '11 at 10:41
...
How to convert all tables from MyISAM into InnoDB?
I know I can issue an alter table individually to change the table storage from MyISAM to InnoDB.
26 Answers
...
How do I UPDATE from a SELECT in SQL Server?
In SQL Server , it is possible to insert rows into a table with an INSERT.. SELECT statement:
35 Answers
...
Rename MySQL database [duplicate]
...p; paste this snippet:
mysql -e "CREATE DATABASE \`new_database\`;"
for table in `mysql -B -N -e "SHOW TABLES;" old_database`
do
mysql -e "RENAME TABLE \`old_database\`.\`$table\` to \`new_database\`.\`$table\`"
done
mysql -e "DROP DATABASE \`old_database\`;"
...
How do I add a foreign key to an existing SQLite table?
I have the following table:
9 Answers
9
...
Check if table exists in SQL Server
I would like this to be the ultimate discussion on how to check if a table exists in SQL Server 2000/2005 using SQL Statements.
...
INSERT INTO vs SELECT INTO
...
They do different things. Use INSERT when the table exists. Use SELECT INTO when it does not.
Yes. INSERT with no table hints is normally logged. SELECT INTO is minimally logged assuming proper trace flags are set.
In my experience SELECT INTO is most commonly used ...
How do you join on the same table, twice, in mysql?
I have 2 tables. One (domains) has domain ids, and domain names (dom_id, dom_url).
3 Answers
...
Add a new column to existing table in a migration
I can't figure out how to add a new column to my existing database table using the Laravel framework.
11 Answers
...
Lock Escalation - What's happening here?
While altering a table (removing a column) in SQL Server 2008, I clicked the Generate Change Script button and I noticed that the change script it generated drops the column, says "go" and then runs an additional ALTER TABLE statement that appears to set the lock escalation for the table to "TABLE"....