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...
This statement is a basic query statement and is used to return the query results.The table to be queried must already exist, or an error message will be displayed.When s
01 Writing Basic SQL SELECT Statements WritingBasicSQLSELECTStatements DatabaseProgramming CopyrightJetPro,2001.Allrightsreserved.Objectives Aftercompletingthislesson,youshouldbeabletodothefollowing:ListthecapabilitiesofSQLSELECTstatementsExecuteabasicSELECTstatement DatabaseProgramming 1-2CopyrightJetPro,2001.Allrights...
For an SQL statement that returns results, such as a SELECT statement, it is rejected as an error unless it has an INTO clause, as described in the next section. Example: PERFORM create_mv('cs_session_page_requests_mv', my_query); Execute a query that returns a single row of data ...
Basic SQL clauses: SELECT, FROM, and WHERE A SQL statement takes the general form: SELECT field_1 FROM table_1 WHERE criterion_1 ; Notes: Access ignores line breaks in a SQL statement. However, consider using a line for each clause to help improve the readability of your SQL...
No more than one SELECT statement can be used in a query that includes other SQL statements. Both simple and bracketed comments can be used in an SQL query. Simple comments are introduced with two consecutive hyphens (--) and end with the end of a line. Simple comments cannot be continued...
SELECT a.deptno INTO v_dept FROM emp a WHERE job="PRESIDENT"; update_commission(v_dept); END / 结构控制: IF...THEN...ELSE/IF...THEN...ELSEIF IF condition1 THEN Statement1; ELSEIF condition2 THEN Statement2; ELSE Statement3;
有時候您的程式碼需要 Unmanaged 資源,例如檔案控制代碼、COM 包裝函式或 SQL 連線。 Using 區塊可確保當您的程式碼完成時,會處置一或多個此類資源。 這可讓其他程式碼使用這些資源。 .NET Framework 記憶體回收行程 (GC) 會處置 Managed 資源,而您無須額外進行編碼。 您不需要 Managed 資源的 Using 區塊。 不...
<MailMergeObject>.OpenDataSource Name:="C:\MyDB.mdb", _ SQLStatement:="SELECT * FROM [MyTable]", _ SubType:=wdMergeSubTypeWord2000 自动化示例 以下示例代码通过使用 OLEDB (通过 ODSO) 创建和执行表单字母的邮件合并。 使用的数据源是示例 Access 数据库 Northwind.mdb。 如果未安装 Northwind,请启...
1. Using the same Select statement you have above, remove the ' ; ' and add where department_id = 100; Click F9. The Results tab shows fewer records returned. 4. Use SQL*Plus commands The SQL Worksheet allows you to use a selection of SQL*Plus commands. SQL*Plus commands have to be...