For example, to select first name and last name of all the students. SELECT first_name, last_name FROM student_details; You can also use clauses like WHERE, GROUP BY, HAVING, ORDER BY with SELECT statement. We will discuss these commands in coming chapters. ...
SELECTcolumn1, column2, ...CASEWHENcondition1THENresult1WHENcondition2THENresult2-- Add more WHEN conditions and results as neededENDASalias_nameFROMtable_name; We can add as manyWHEN ... THENconditions as required in theCASEstatement. For example, -- multiple CASE conditions in SQLSELECTcusto...
Here, the SQL command copies all records from theCustomerstable to theOldCustomerstable. INSERT INTO SELECT Syntax The syntax of the SQLINSERT INTO SELECTstatement is: INSERTINTOdestination_table (column1, column2, column3, ...)SELECTcolumn1, column2, column3, ...FROMsource_table; Here, des...
Capabilities of theSELECTStatement(SELECT语句的功能) Data retrieval from data base is done through appropriate and efficient use of SQL. Three concepts from relational theory encompass the capability of the SELECT statement: projection, selection, and joining. Projection(投影): A project operation sele...
[:]退出 [ ( statement ) ] 可讓您使用 SELECT 陳述式的結果作為 sqlcmd 的傳回值。 如果為數值,最後一個結果資料列的第一個資料行會轉換成 4 位元組的整數 (long)。 MS-DOS、Linux 和 macOS 會將低位元組傳遞給父處理序或作業系統錯誤級別。 Windows 2000 和更新版本會傳遞完整的 4 位元組整數。 語法...
Query hints can't be specified in an INSERT statement, except when a SELECT clause is used inside the statement. Query hints can be specified only in the top-level query, not in subqueries. When a table hint is specified as a query hint, the hint can be specified in the to...
SELECT with DISTINCT on multiple columns and ORDER BY clause You can use an order by clause in the select statement with distinct on multiple columns. Here is an example: SQL Code: SELECT DISTINCT agent_code, ord_amount -- Select distinct combinations of 'agent_code' and 'ord_amount' ...
Learn the SQL SELECT statement to retrieve data from your database efficiently. Explore examples and syntax to master SQL queries.
-- 错误用法：财务系统查询加NOLOCK SELECT Balance FROM Accounts WITH(NOLOCK) WHERE UserID = 1001...
This SQL tutorial explains how to use the SQL AND condition with syntax and examples. The SQL AND condition (also known as the AND Operator) is used to test for two or more conditions in a SELECT, INSERT, UPDATE, or DELETE statement.