大约有 47,000 项符合查询结果(耗时:0.0338秒) [XML]

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How to export all data from table to an insertable sql format?

... top level of the context menu Thanks to Daniel for the comment to update. Select generate scripts Click next Choose tables Click next Click advanced Scroll to Types of data to script - Called types of data to script in SMSS 2014 Thanks to Ellesedil for commenting Select data only Click on 'Ok' to c...
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SQL Server CTE and recursion example

...The query finds all root nodes as described by WHERE ManagerID IS NULL SELECT EmployeeID, FirstName, LastName, ManagerID, 1 FROM Employees WHERE ManagerID IS NULL -->>>>>>>>>>Block 1>>>>>>>>>>>>>>>>> UNI...
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How to select only 1 row from oracle sql?

I want to use oracle syntax to select only 1 row from table DUAL . For example, I want to execute this query: 13 Answers ...
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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]

...for all your queries that need to count everything, even for joins, use * SELECT boss.boss_id, COUNT(subordinate.*) FROM boss LEFT JOIN subordinate on subordinate.boss_id = boss.boss_id GROUP BY boss.id But don't use COUNT(*) for LEFT joins, as that will return 1 even if the subordinate table doe...
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PostgreSQL return result set as JSON array?

... TL;DR SELECT json_agg(t) FROM t for a JSON array of objects, and SELECT json_build_object( 'a', json_agg(t.a), 'b', json_agg(t.b) ) FROM t for a JSON object of arrays. List of objects This section de...
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Fastest way to determine if record exists

... SELECT TOP 1 products.id FROM products WHERE products.id = ?; will outperform all of your suggestions as it will terminate execution after it finds the first record. ...
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Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc

I've heard that SELECT * is generally bad practice to use when writing SQL commands because it is more efficient to SELECT columns you specifically need. ...
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How to set selected value on select using selectpicker plugin from bootstrap

I'm using the Bootstrap-Select plugin like this: 18 Answers 18 ...
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Can you have if-then-else logic in SQL? [duplicate]

I need to do select data from a table based on some kind of priority like so: 7 Answers ...
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How to ensure a form field is submitted when it is disabled?

I have a select form field that I want to mark as "readonly", as in the user cannot modify the value, but the value is still submitted with the form. Using the disabled attribute prevents the user from changing the value, but does not submit the value with the form. ...