ArcerZhang`s Technology Blog

摘要： ObjectivesAfter completing this lesson,you should be able to do the following:Identify lexical units in a PL/SQL block.Use build-in SQL functions in PL/SQLDescribe when implict conversions take place and when explict conversion have to be dealt withWrite nested blocks and qualify variables with labe 阅读全文

摘要： Types of VariablesGuidelines for Declaring and Inititalizing PL/SQL VariablesFollow naming conventions.Use meaningful identifiers for variables.Initialize variables designated as NOT NULL and CONSTANT.Initialize variables with the assignment operator (:=) or the DEFAULT keyword:v_myName VARCHAR2(20) 阅读全文

摘要： ObjectivesAfter completing this lesson,you should be able to do the followingRecognize valid and invalid identifies.List the uses of variables.Declare and initialize variables.List and descible various data types.Indentify the benefits of using the %TYPE attribute.Declare,useand print bind variables 阅读全文

摘要： ObjectivesAfter completing this lesson,you should be able to do the following:Explain the need for PL/SQLExplain the benefits of PL/SQLIndentify the different types of PL/SQL blocksOut messages in PL/SQLAbout PL/SQLStands for "Procedural Language extension to SQL".Is Oracle Corporation`s s 阅读全文

摘要： OjbectivesAfter completing this lesson,you should be able to do the following:Describle the course organizationDescrible the sample HR schemaCourse ObjectivesAfter completing this lesson,you should be able to do the following:Identify the programming extensions that PL/SQL provdies to SQL.Write PL/S 阅读全文

摘要： Rolling Back Changers to a MarkerCreate a marker in the current transaction by using the SAVEPOINT statement.Roll back to that marker by using the ROLLBACK TO SAVEPOINT statement.UPDATE ...SAVEPOINT update_done;INSERT ...ROLLBACK TO update_done;Implict Transaction ProcessingAn automatic commit occur 阅读全文

摘要： Changing Data in a TableUPDATE Statement SyntaxModify existing values in a table with the UPDATE statementUPDAE tableSET column = value [,column = value,...][WHERE condition];Update more than one row at a time(if required)Updating Rows in a TableValuesfor a specific row or rows are modified if you s 阅读全文

摘要： ObjectivesAfter completing this lesson,you should be able to do the following:Describe each data manipulation language(DML) statement.Insert rows into a table.Update rows in a table.Delete rows from a table.Control transactions.Lesson AgendaAdding new rows in a table-INSERT statementChanging data in 阅读全文

摘要： ObjectivesAfter completing this lesson,you should be able to do the following:Describe set operators.Use a set operator to combine multiple queries into a single query.Control the order of rows returned.Lesson AgendaSet Operators:Types and guidelinesTables used in this lessonUNION and UNION ALL oper 阅读全文

摘要： ObjectivesAfter completing this lesson,you should be able to do the following:Define subqueries.Describe the types of problems that the subqueries can solve.List the types of subqueries.Write single-row and multiple-row subqueries.single-row:查询结果返回一条记录multiple-row:查询结果返回多条记录Lesson AgendaSubquery:Typ 阅读全文