You can bind only variable values. You can’t bind in the names of tables or columns, nor can you bind in parts of a SQL statement structure, such as the entire WHERE clause. In these cases, you must use concatenation. Example Here’s an example of binding with DBMS_SQL. This progr...
ensuring the optimal choice of cursor for a specificbind value. For example, the optimizermight choose one plan for bind value 9 and a different plan for bind value 10.Cursor sharing is "adaptive" because the cursor adapts its behaviorso that the same plan is not always used for each...
PL/SQL units areaffected by PL/SQL compilation parameters (a categoryof database initializationparameters). Different PL/SQL units—for example, a package specification andits body—can have different compilation parameter settings. --PL/SQL 单元受PL/SQL 编译参数的影响,不同的单元可以设置不同的编译...
stmt :='delete from emp where deptno = :dept_array';/* A Dynamic SQL String with a bind variable */c :=DBMS_SQL.OPEN_CURSOR;/* Open a Cursor! */DBMS_SQL.PARSE(c, stmt, DBMS_SQL.NATIVE);/* Parse the Dynamic SQL , making it happen on the native database to which is connected!
For example,Oracle Forms applications frequently use SQL statements to test the values offield entries and do simple computations. By using PL/SQL instead of SQL, theseapplications can avoid calls to the database. 2.2 PL/SQL Unitsand Compilation Parameters ...
The following example shows how to create a simple alias:SQL> ALIAS action1=select :one from dual; Note: Define an alias simply by using the alias keyword followed by a single identifier name followed by an '='. Anything after the '=' will be used as the alias contents. If it is ...
The following example illustrates this by repeating the previous test, this time using substitution variables.SQL> alter system flush shared_pool; System altered. SQL> select * from dual where dummy = '&dummy'; Enter value for dummy: SUBSTITUTION_VARIABLE1 old 1: select * from dual where ...
In the last example, when the identifiersalaryis used in the cursor declaration, it refers to the formal parameter. But, when it is used in theOPENstatement, it refers to the PL/SQL variable. To avoid confusion, use unique identifiers. ...
The PL/SQL block inExample 6-10queries multiple values into PL/SQL tables, with and without bulk binds. Without bulk bind, PL/SQL sends a SQL statement to the SQL engine for each selected employee, leading to context switches that slow performance. ...
本地动态SQL可以在pl/sql中直接执行,支持如下调用方法: EXECUTE IMMEDIATE OPEN-FOR FETCH CLOSE 使用EXECUTE IMMEDIATE 可以使用 EXECUTE IMMEDIATE 在本地运行动态SQL和匿名块: EXECUTEIMMEDIATEdynamic_string[INTO{diefine_variable[,define_variable]...|record}][USING[IN|OUT|INOUT]bind_argument[,[IN|OUT|INOUT...