The Ultimate Guide to Oracle solaris 11 installation and configuration essentials 1 z0 580
- 1. The Ultimate Guide to Oracle Solaris 11 Installation and Configuration Essentials 1Z0- 580 Oracle Solaris 11 Installation and Configuration Essentials 1Z0-580 Certification Exam Credential Data manipulation language (DML) statements add, change, and delete Oracle Database table data. A transaction is a sequence of one or more SQL statements that Oracle Database treats as a unit: either all of the statements are performed, or none of them are. About Data Manipulation Language (DML) Statements Data manipulation language (DML) statements access and manipulate data in existing tables. About Transaction Control Statements A transaction is a sequence of one or more SQL statements that Oracle Database treats as a unit: either all of the statements are performed, or none of them are. You need transactions to model business processes that require that several operations be performed as a unit. Committing Transactions Committing a transaction makes its changes permanent, erases its savepoints, and releases its locks. Rolling Back Transactions Rolling back a transaction undoes its changes. You can roll back the entire current transaction, or you can roll it back only to a specified savepoint. Setting Savepoints in Transactions The SAVEPOINT statement marks a savepoint in a transaction—a point to which you can later roll back. Savepoints are optional, and a transaction can have multiple savepoints. 3.1 About Data Manipulation Language (DML) Statements
- 2. Data manipulation language (DML) statements access and manipulate data in existing tables. In the SQL*Plus environment, you can enter a DML statement after the SQL> prompt. In the SQL Developer environment, you can enter a DML statement in the Worksheet. Alternatively, you can use the SQL Developer Connections frame and tools to access and manipulate data. To see the effect of a DML statement in SQL Developer, you might have to select the schema object type of the changed object in the Connections frame and then click the Refresh icon. The effect of a DML statement is not permanent until you commit the transaction that includes it. A transaction is a sequence of SQL statements that Oracle Database treats as a unit (it can be a single DML statement). Until a transaction is committed, it can be rolled back (undone). For more information about transactions, see "About Transaction Control Statements". 3-1 About the INSERT Statement The INSERT statement inserts rows into an existing table. About the UPDATE Statement The UPDATE statement updates (changes the values of) a set of existing table rows. About the DELETE Statement The DELETE statement deletes rows from a table. See Also: Oracle Database SQL Language Reference for more information about DML statements 3.1.1 About the INSERT Statement The INSERT statement inserts rows into an existing table. The simplest recommended form of the INSERT statement has this syntax: INSERT INTO table_name (list_of_columns) VALUES (list_of_values);
- 3. Every column in list_of_columns must have a valid value in the corresponding position