Aclause(子句)is a part of a SQL statement(Select语句的一个组成部分) ——for example,SELECT emplovee_id, last_name, and so on Astatement(语句)is a combination(组合)of two or more clauses(Select语句是两个或者多个子句的组合) ——for example,SELECT * FROM employees(SELECT *叫一个子句,FR...
_ tname, "s"){ #; GOTO SpecifyQuery #; } else { #; w "Table unavailable" #; q #; } #;SpecifyQuery s myquery = 3 s myquery(1) = "SELECT Home_State,Name,SSN,Age" s myquery(2) = "FROM Sample.Person" s myquery(3) = "ORDER BY Name" s tStatement = ##class(%SQL.St...
靜態SELECT 陳述式 對於靜態 SELECT 陳述式 (SQL 程式中內嵌的陳述式) ,必須在 FROM 子句之前指定 INTO 子句。 處理空值 空值表示列中沒有直欄值。 空值是不明值; 它與零或全部空白不同。 SQL 陳述式中的特別暫存器 您可以在 SQL 陳述式中指定某些特別暫存器。特別暫存器(例如 CURRENT DATE) 包含可在 SQL ...
();Stringsql="SELECT * FROM customers";ResultSetresultSet=statement.executeQuery(sql);while(resultSet.next()){intid=resultSet.getInt("id");Stringname=resultSet.getString("name");Stringemail=resultSet.getString("email");System.out.println("ID: "+id+", Name: "+name+", Email: "+email...
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. ...
SELECT * FROM orders WHERE username = 'lily' AND orderprice >= 100; 关于操作符的更多信息,请参见SQL操作符。 GROUP BY分组查询(groupby_condition) 通过GROUP BY子句对SELECT语句的结果集按照指定条件进行分组。使用规则如下: 按照字段分组 SELECT username FROM orders GROUP BY username; 在分组的列上支持使...
In SQL, the SELECT INTO statement is used to copy data from one table to another. Example -- copy all the contents of a table to a new table SELECT * INTO CustomersCopy FROM Customers; Here, the SQL command copies all data from the Customers table to the new CustomersCopy table. ...
The SELECT statement is a common SQL statement. You’ll use it all the time. It can be as simple as selecting a few columns from a table, or it can include joins, functions, and grouping. You can also use subqueries and other more advanced features with it....
文档中心 参考手册 SQL语法 语句 select selectselect 用于从集合中选取数据,结果被存储在一个结果集中。语法select < * | field1_name,field2_name,... | mathematical_expression > from <cs_name.cl_name | statement> [clause]如:select * from <cs_name>.<cl_name>...
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; ...