Pl/sql Syntax Structure

[sameh bakkar]

بسم الله الرحمن الرحيم ....
أعلم جيدا أنك فى حاجه الى ملخص سريع تسترجع به ال PL/SQL Syntax نظرا لصعوبة المراجعه من كتاب او ما شابه ذلك .. لذلك فقد قمت بإعداد هذا الملخص ليكون مرجع سريع لك .. وانا ارى انه مفيد جدا .... و ان شاء الله سوف اقوم بإعداد مثله فى جمل ال SQL.... بسم الله نبدأ

Procedure: 
PROCEDURE name (p_parm1 IN|INOUT datatype, … ) 
/* declarations */ 
IS 
BEGIN 
/* executable code */ 
EXCEPTION 
/* error handling */ 
END name; 
/ 
 
Function: 
FUNCTION name name (p_parm1 IN|INOUT datatype, … ) 
  RETURN datatype 
/* declarations */ 
IS 
BEGIN 
/* executable code */ 
EXCEPTION 
/* error handling */ 
END name; 
/ 
 
Anonymous Block: 
DECLARE 
/* declarations */ 
IS 
BEGIN 
/* executable code */ 
EXCEPTION 
:/* error handling */ 
END name; 
/ 
 
All PL/SQL functions and procedures, including packaged procedures and anonymous blocks follow the above basic layout:  If you don’t name the PL/SQL procedure, you call it an 'anonymous block' 
 

CLOSE Syntax Statement

CLOSE cursor_name; 
 
Closing a cursor releases the context area.

CURSOR Syntax Statement

CURSOR cursor_name 
 IS select_statement; 
 
CURSOR cursor_name 
 [(parameter_name datatype, ...)] 
	IS select_statement; 
 
Cursor parameters follow the syntax 
  cursor_parameter [iN] datatype [{:= | DEFAULT} expr]

Cursor Attributes

cursor%ROWCOUNT   - int - number of rows affected by last SQL statement 
cursor%FOUND	 - bool - TRUE if >1 row returned 
cursor%NOTFOUND  - bool - TRUE if 0 rows returned 
cursor%ISOPEN	- bool - TRUE if cursor still open

CURSOR in FOR LOOP Statement

When you use FOR-LOOP statement, all open, fetch, and close functions are inclusive. 
Example: 
BEGIN 
  FOR myrecord IN (SELECT c1, c2 FROM mytable) LOOP 
  -- implicit open/fetch occurs 
  IF myrecord.c1 = 1 THEN 
	…… 
  END IF; 
  END LOOP; -- implicit CLOSE occurs 
END; 
/ 
 
Cursor with Parameters 
BEGIN 
  FOR trip_record IN trip_cursor(12, 3) LOOP ... 

DECLARE Section

Declare variables and constants in a PL/SQL declare block.
name [CONSTANT] datatype [NOT NULL]  [:= | DEFAULT expr]
 
key
name	  : The name of the variable
datatype  : may be scalar, composite, reference or LOB
expr	  : a literal value, another variable or any plsql expression involving operators & functions.

A constant MUST have it's initial value in the declaration.
Composite datatypes are TABLE, RECORD, NESTED TABLE and VARRAY
You can use [schema.]object%TYPE to define variables based on actual object datatypes.

Declaring RECORD variables
A specific RECORD TYPE corresponding to a fixed number (and datatype) of underlying table columns can simplify the job of defining variables.
Syntax:
TYPE type_name IS RECORD
  (field_declaration,...);
 
Options
'field_declaration' is defined as:
field_name {datatype | variable%TYPE | table.column%TYPE | table%ROWTYPE}[ [NOT NULL] {:= | DEFAULT} expr ]
 
Declare %ROWTYPE% Record variables:
DECLARE
  variable_name table_name%ROWTYPE%  
At runtime the system will evaluate the number of variables and their datatype; The columns may be based on an underlying table or a cursor.

Declare SQL*Plus bind variables.
Syntax:
SQL > VARIABLE g_bar VARCHAR2(30)
SQL > ACCEPT p_foo PROMPT 'enter the value required'
You can reference host variables in PL/SQL statements *unless* the statement is in a procedure, function or package.  This is done by prefixing with & (to read the variable) or prefix with : (writing to the variable)


Example:
-- Declare a variable based on SQL*Plus Bind variable
  v_amount NUMBER(6,2) := &p_foo
 
-- Assign value to a SQL*Plus variable from a PL/SQL variable
  :g_bar := v_amount *12
 
Declare TABLE TYPE variables in a PL/SQL declare block.
Table variables are also known as index-by table or array. The table variable contains one column which must be a scalar or record datatype plus a primary key of type BINARY_INTEGER.
Syntax:
  DECLARE
  TYPE type_name IS TABLE OF
  (column_type |
  variable%TYPE |
  table.column%TYPE
	 [NOT NULL]
		INDEX BY BINARY INTEGER; 
 
-- Then to declare a TABLE variable of this type:
  variable_name type_name;
 
-- Assigning values to a TABLE variable:
  variable_name(n).field_name := 'some text';  -- Where 'n' is the index value
 
Using TABLE variable Methods:
To execute these use the syntax:   table_name[ (parameters)]
EXISTS(n)   Returns TRUE if nth element of the table exists.
COUNT	   The number of elements (rows) in the plsql table
FIRST	   First and Last index no.s in the table
LAST		returns NULL if table is empty
PRIOR(n)	Returns index no that preceeds n in the plsql table
NEXT(n)	 Returns index no that succeeds n in the plsql table
EXTEND(n,i) Append n copies of the 'i'th element to a plsql table i defaults to NULL n defaults to 1
TRIM(n)	 Remove n elements from the end of a plsql table n defaults to 1
DELETE(m,n) Delete elements in range m...n (m defaults to = n and n defaults to ALL elements
[code]

[code]
DECLARE, OPEN, CLOSE a REF CURSOR Syntax Statement 
TYPE ref_type_name IS REF CURSOR
  [RETURN {cursor_name%ROWTYPE
		 | ref_cursor_name%ROWTYPE
		 | record_name%TYPE
		 | record_type_name
		 | table_name%ROWTYPE} ];
 
Then:  ref_cursor_name ref_type_name;
 
OPEN a REF cursor...
 OPEN cursor_variable_name FOR select_statement;
CLOSE a REF cursor: 
 CLOSE {cursor_name | :host_cursor_variable_name}; 
 
Example:
 IF NOT mycursor%ISOPEN THEN
OPEN mycursor FOR select_statement;
CLOSE mycursor;
 END IF;
 
REF Cursor Attributes : 
cursor%ROWCOUNT   - int - number of rows affected by last SQL statement 
cursor%FOUND	 - bool - TRUE if >1 row returned 
cursor%NOTFOUND  - bool - TRUE if 0 rows returned 
cursor%ISOPEN	- bool - TRUE if cursor still open 
 

EXCEPTION Syntax

 
EXCEPTION
  WHEN exception1 [OR exception2...]] THEN
  ...
  [WHEN exception3 [OR exception4...] THEN
  ...]
  [WHEN OTHERS THEN
  ...]
 
Where exception is the exception_name e.g. NO_DATA_FOUND, etc. Note that only one handler is processed before leaving the block.
 
Trap non-predefined errors by declaring them and using the PRAGMA EXCEPION_INIT pragma.
When an exception occurs you can identify the associated error code/message with two supplied functions SQLCODE and SQLERRM (SQLCODE – Number and SQLERRM – message)
 
If a sub block does not have a handler for a particular error it will propagate to the
enclosing block - where it can be caught by more general exception handlers.
 
RAISE_APPLICATION_ERROR (error_no, message[,{TRUE|FALSE}]);

FETCH Syntax Statement

FETCH cursor_name INTO [variable1, variable2,...]
					 | record_name;
 
The variables must match (both in number and positionally) the columns listed in the cursor definition.

FOR-LOOP Syntax Statement

FOR counter in [REVERSE] 
  lower_bound..upper_bound LOOP 
  statement1; 
  statement2; 
... 
END LOOP; 
 
A PL/SQL FOR Loop will implicitly declare a counter, or cursor variable. Remember that open, fetch, close functions are all implicit in the FOR-LOOP statement. 
 

IF-THEN-END IF Syntax Statement

IF condition THEN 
  statements; 
[ELSEIF condition THEN 
  statements;] 
[ELSE 
  statement;] 
END IF; 
 
NOTE: 
null AND null = null 
null OR null = null 
true AND null = null 
true OR null = true 
false AND null = false 
false OR null = null 
NOT NULL = NULL

LOOP Syntax Statement

LOOP 
  STATEMENT1; 
  ... 
  EXIT [WHEN condition]; 
END LOOP; 
 

OPEN Syntax Statement

OPEN cursor_name; 
OPEN cursor_name param1 param2...; 

PL/SQL Operators

Comparison Operators
  + - * / @ ;  =  <>  !=  ||  <=  >=
  NOT  IS NULL
  LIKE 
  BETWEEN 
  IN 
  AND 
  OR
 
Comments
  -- comment
  /* comment */
  << Begin label - end label >>
 
Assignment operator
  :=
 
Exponential operator (valid for plsql only)
  **
 
Delimiters
Item separator .
Character string delimiter '
Quoted String delimiter "
Bind variable indicator :
Attribute indicator %
Statement terminator ;
 
Functions
All SQL functions that return a single row can be used in a plsql procedural statement. Note that the Group and DECODE functions are not supported.
 
Examples
v_myDate := TO_DATE('01-OCT-2001',DD-MON-YYYY)

WHILE-LOOP Syntax Statement

WHILE condition LOOP 
  statement1; 
  statement2; 
... 
END LOOP; 

تـــرقبــــــــــــــوا ملخص جمل الــSQL إن شـــــــــاء الله

[Jasmin]

بسم الله ما شاء الله ........ بجد تستاهل الدعاء يا بشنهندس وماما بجد بتدعيلك لما أقرأ لها موضوعاتك الجميله دى واد ايه حضرتك بتتعب عشان المبتدئين .... الله يبارك فيك و يزيدك من علمه انا فعلا كنت محتاجه الملخص دا عشان عندى مقابله بعد يومين .. أدعولى يا أخوانى ان يوفقنى الله

[المبرمج الصاعد]

السلام عليكم؟؟؟؟

تسلم يا مشرفنا العزيز على هذه الملخص الجميل جدا جدا

وأسال الله أن يبارك فيك وفي علمك

[جلال شواقفه]

وفقك الله وسدد خطاك
وبارك الله بك وعملك وعلمك
وادام الصحه والعافيه عليك

تم تعديل 1 نوفمبر 2007 بواسطة JLL_JORDAN_1

[no_Mercu]

والله انت وردة يا بش مهندس سامح

[ra7l]

اتشوق لمواضيعك وملخصاتك دائما ,,

الله يعطيك العافيه يا مهندس

[احسان الشامي]

زادك الله في العلم النافع يا مهندس سامح

ونفع بك الاسلام والمسلمين والبشرية أجمعين

جعل الله جهدك ووقتك هذا في ميزان حسناتك