The tables in the following sections provide a functional summary of SQL statements and fall into the following categories: All transaction control statements, except some forms of COMMIT and ROLLBACK commands, are supported in PL/SQL. For more information about restrictions, see COMMIT and ROLLBACK. PL/SQL does not support session control statements. The session control statements are as follows: The number of columns in the column_list must match the number of expressions in the subquery. FORCE creates the view regardless of whether there are base tables or referenced object types, or whether the owner of the schema that contains the view has permissions. These conditions must be met before SELECT, INSERT, UPDATE, or DELETE statements can be issued in the view. If you are not already involved in a transaction, Oracle Lite starts a transaction the first time you issue a SQL statement. Any statements you issue are considered part of the transaction until you use a COMMIT or ROLLBACK command. SQL commands that deal with manipulating the data in the database belong to DML or Data Manipulation Language, and this includes most SQL statements. It is the component of the SQL statement that controls access to the data and database. Basically, DCL instructions are bundled with DML statements.
If the user does not specify the list of columns, an error message is returned. CREATE SCHEMA treats a set of separate statements as a single statement. If one of their constitutive declarations fails, all their instructions are reversed. You can use Data Definition Language (DDL) statements to perform the following tasks: With the exception of restricting the OUT and IN OUT parameters, Oracle Database Lite applies these restrictions not only to the function called directly by the SQL statement, but also to all functions called by the function. Oracle Database Lite also applies these restrictions for all functions called by SQL statements executed by that function or for any function that calls them. Session control statements dynamically manage the properties of a user session. These statements are not implicitly involved in the current transaction. Oracle Lite combines certain permissions into predefined roles. In many cases, it is easier to assign a predefined role to a user than to grant specific permissions in another schema. Oracle Lite does not support creating or deleting roles. The predefined Oracle Lite roles are listed in Table 4-43: CREATE statements are used to define the database structure schema: The syntax for the add_column_list expression is shown in Figure 4-4. The CREATE SCHEMA statement can contain the CREATE TABLE, CREATE VIEW, and GRANT statements.
To issue a CREATE SCHEMA statement, you must be connected to the database as a SYSTEM or as a user with DBA/DDL or ADMIN privileges. The SELECT list of a SELECT statement that is not in a subquery, materialized view, or view. If an expression in the select list contains an alias, the alias is used as the column name. DQL statements are used to execute queries against data contained in schema objects. The purpose of the DQL command is to retrieve a schema relationship based on the query passed to it. We can define DQL as follows, it is a component of the SQL statement that allows you to extract data from the database and impose an order on it. It contains the SELECT statement. This command can be used to retrieve data from the database for operations. When a SELECT is triggered for one or more tables, the result is compiled into another temporary table that is displayed or optionally received by the program, that is, a front-end interface. Here are the different types of SQL commands, including clauses and pseudo-columns.
For an explanation of each SQL command, clause, and pseudocolumn, see SQL Command Overview. DDL statements are supported by PL/SQL using the DBMS_SQL package. If privilege_list is ALL, the user can select INSERT, DELETE, UPDATE, or SELECT from the table or view. If privilege_list is INSERT, DELETE, UPDATE, or SELECT, the user has this permission on a table. If privilege_list contains INSERT, DELETE, UPDATE, or SELECT, the user has these permissions on a table or view. If privilege_list is ALL, the user can select INSERT, DELETE, UPDATE, or SELECT from the table or view. The SELECT list of a subquery in an INSERT statement. embedded SQL statements place DDL, DML, and transactional control statements in a procedural language program. Embedded SQL is supported by Oracle precompilers and is documented in the following manuals: The expression expr sorts rows by their value for expr. The expression is based on columns in the select list or columns in tables, views, or snapshots in the FROM clause. No column references in the select list point to the same column. To then insert them into table t1, the insert statement can omit the list of columns as shown below.
To avoid the list of columns in the insert statement, the automatically incremented column can be hidden before the INSERT command is issued. For example, if we issued the following ALTER command. CALL and EXPLAIN PLAN statements are supported in PL/SQL only when executed dynamically. All other DML statements are fully supported in PL/SQL. Commit or cancel the current transaction, create or cancel a savepoint, or modify the session or system. DDL statements implicitly pass the current transaction, so a user-defined function cannot execute DDL statements. The OL__ROW_STATUS pseudocolumn can be qualified with the table name in the same way as other pseudocolumns.