大约有 37,000 项符合查询结果（耗时：0.0520秒） [XML]
Real life example, when to use OUTER / CROSS APPLY in SQL
...ORDER BY pr.name) pa
ORDER BY pr.name,
pa.name
2) Calling a Table Valued Function for each row in the outer query
SELECT *
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle)
3) Reusing a column alias
SELECT number,
doubled_number,
...
SQL JOIN - WHERE clause vs. ON clause
...r join has taken place.
b. ON clause - Before joining. Records (from right table) will be filtered before joining. This may end up as null in the result (since OUTER join).
Example: Consider the below tables:
1. documents:
| id | name |
--------|-------------|
| 1 ...
Do I need to create indexes on foreign keys on Oracle?
I have a table A and a table B . A has a foreign key to B on B 's primary key, B_ID .
7 Answers
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Import CSV to SQLite
I'm trying to import a csv file to an SQLite table.
10 Answers
10
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SQL ON DELETE CASCADE, Which Way Does the Deletion Occur?
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Cascade will work when you delete something on table Courses. Any record on table BookCourses that has reference to table Courses will be deleted automatically.
But when you try to delete on table BookCourses only the table itself is affected and not on the Courses
foll...
Log all queries in mysql
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Is it possible to log queries over 1 particuarl db / table only?
– Temujin
Aug 4 '12 at 16:08
2
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select into in mysql
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Use the CREATE TABLE SELECT syntax.
http://dev.mysql.com/doc/refman/5.0/en/create-table-select.html
CREATE TABLE new_tbl SELECT * FROM orig_tbl;
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CSS center text (horizontally and vertically) inside a div block
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Since they tend to be hacks or adding complicated divs... I usually use a table with a single cell to do it... to make it as simple as possible.
Update for 2020:
Unless you need make it work on earlier browsers such as Internet Explorer 10, you can use flexbox. It is widely supported by all cur...
Adding a column to an existing table in a Rails migration
...e the add_column line completely (that code is trying to add a column to a table, before the table has been created, and your table creation code has already been updated to include a t.string :email anyway).
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Transaction isolation levels relation with locks on table
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I want to understand the lock each transaction isolation takes on the table
For example, you have 3 concurrent processes A, B and C. A starts a transaction, writes data and commit/rollback (depending on results). B just executes a SELECT statement to read data. C reads and updates data. All t...