Note:Throughout this course, the wordskeyword,clause, andstatementare used as follows: Akeyword(关键字)refers to an individual(独特的)SQL element(有特殊含义的SQL元素) ——for example,SELECTandFROMare keywords. Aclause(子句
NOTE: SQL commands are not case sensitive. The above SELECT statement can also be written as"select first_name from students_details;" You can also retrieve data from more than one column. For example, to select first name and last name of all the students. ...
TheSELECTstatement is used to select data from a database. ExampleGet your own SQL Server Return data from the Customers table: SELECTCustomerName, CityFROMCustomers; Try it Yourself » Syntax SELECTcolumn1,column2, ... FROMtable_name; ...
sql语句select用法详解(SQL statement select usage detailed) SQL statement select usage detailed SELECT-SQL command detailed Select - SQL command Retrieve data from one or more tables. grammar SELECT [ALL DISTINCT] [TOP nExpr [PERCENT]] | [Alias.] Select_Item [AS Column_Name] [[Alias.], Sele...
SQL SELECT Statement – Selecting individual fields from a table We can use the SQL SELECT Statement to select and view only certain fields from a table. For example, the below SQL SELECT Statement query will return “employee_id”, “employee_name” and “department” fields only from the ...
executeQuery(String sql) 是java.sql.Statement 接口中的一个方法,专门用于执行静态 SQL 查询并返回它所生成结果的对象。此方法通常用于执行诸如 SELECT 这样的查询语句,它会返回一个 ResultSet 对象,该对象包含了从数据库中检索到的数据。 语法 ResultSet executeQuery(String sql) throws SQLException; 参数: sql...
The SELECT statement inSQLisused to retrieve rows from a database table. It lets you specify which columns of the table to fetch and the criteria for rows. The data returned is called a result set and is displayed in your development tool or used by the application that ran the query. ...
Statement:语句,通常指整个SQL文本 Clause:子句,通常指SQL文本中的一部分,如From子句、Where子句、Group By子句 Query:查询,通常指SQL文本在系统中的一次执行实例 Database:库,一个库可以有多个表;含义类似的有:模式(Schema) Table:表,一个表可以有很多行;含义类似的有:关系(Relation) Row:行,一行可以有很多列;...
SQLstatementselectusagedetailed SELECT-SQLcommanddetailed Select-SQLcommand Retrievedatafromoneormoretables. grammar SELECT[ALLDISTINCT][TOPnExpr[PERCENT]]| [Alias.]Select_Item[ASColumn_Name] [[Alias.],Select_Item,[AS,Column_Name]...] FROM[FORCE] ...
SQL SELECT Syntax The syntax of the SQLSELECTstatement is: SELECTcolumn1, column2, ...FROMtable; Here, column1, column2, ...are the table columns tableis the table name from where we select the data For example, -- select first_name and last_name columns from Customers tableSELECTfirst...