
sql是什么,通俗的说,太专业听不懂? - 知乎
SQL是一种用于处理数据的语言,就像我们说的汉语、英语一样,有特定的语法结构,让我们灵活地处理数据。 SQL并不难学,首先得理解 S Q L 三个字母分别代表什么。 Structured Query Language,简 …
How do I perform an IF...THEN in an SQL SELECT?
Sep 15, 2008 · The CASE statement is the closest to IF in SQL and is supported on all versions of SQL Server.
SQL: IF clause within WHERE clause - Stack Overflow
Sep 18, 2008 · Is it possible to use an IF clause within a WHERE clause in MS SQL? Example: WHERE IF IsNumeric(@OrderNumber) = 1 OrderNumber = @OrderNumber ELSE OrderNumber LIKE '%' + @
What is the use of the square brackets [] in sql statements?
The Microsoft book for SQL course says "You should use two-part names to refer to tables in SQL Server databases, such as Sales.Customer" so they don't ask to surround namespace with square …
SQL - Select first 10 rows only? - Stack Overflow
Dec 12, 2009 · How do I select only the first 10 results of a query? I would like to display only the first 10 results from the following query: SELECT a.names, COUNT(b.post_title) AS num FROM
Finding and deleting duplicate values in a SQL table
Jul 28, 2019 · It uses a common table expression (CTE) and a partition window (I think these features are in SQL 2008 and later). This example finds all students with duplicate name and dob.
sql server - SQL MAX of multiple columns? - Stack Overflow
Mar 8, 2012 · How do you return 1 value per row of the max of several columns: TableName [Number, Date1, Date2, Date3, Cost] I need to return something like this: [Number, Most_Recent_Date, Cost] …
sql server - Database stuck in "Restoring" state - Stack Overflow
Ran into a similar issue while restoring the database using SQL server management studio and it got stuck into restoring mode. After several hours of issue tracking, the following query worked for me.
sql - Find all tables containing column with specified name - Stack ...
@Revious INFORMATION_SCHEMA views included in SQL Server comply with the ISO standard definition for the INFORMATION_SCHEMA., sys.columns, sys.tables is Microsoft Sql Server specific.
SQL to find the number of distinct values in a column
SQL to find the number of distinct values in a column Asked 17 years, 1 month ago Modified 2 years, 7 months ago Viewed 825k times