Oracle 8iOracle 8i

Building PL/SQL BlocksBuilding PL/SQL Blocks

Creating PL/SQL BlocksCreating PL/SQL Blocks

• CURSORS

• PROCEDURES

• FUNCTIONS

• PACKAGES

• TRIGGERS

• CURSORS

• PROCEDURES

• FUNCTIONS

• PACKAGES

• TRIGGERS

Structures of a PL/SQL blockStructures of a PL/SQL block

• The Declaration section• The Execution section• The Exception section

DECLARE---BEGIN---EXCEPTION---END;

• The Declaration section• The Execution section• The Exception section

DECLARE---BEGIN---EXCEPTION---END;

Declaration SectionDeclaration Section

• Datatypes:• NUMBER

– 10-130 10125

– NUMBER, NUMBER(PRE),NUMBER(PRE,SC)– Default precision – 38– Scale: -84 to 127 (auto round)– Subtypes:

• DEC/DECIMAL/NUMERIC – fixed point• FLOAT – 128BIT• REAL – 64BIT• INT/INTEGER/SMALLINT

• Datatypes:• NUMBER

– 10-130 10125

– NUMBER, NUMBER(PRE),NUMBER(PRE,SC)– Default precision – 38– Scale: -84 to 127 (auto round)– Subtypes:

• DEC/DECIMAL/NUMERIC – fixed point• FLOAT – 128BIT• REAL – 64BIT• INT/INTEGER/SMALLINT

CharactersCharacters

• CHAR – max 2000 chars (default: 1)

• CHARACTER – same(ANSI)

• VARCHAR2 – max 4000 chars

• NCHAR

• NVARCHAR

• LONG – Up To 2GB

• CHAR – max 2000 chars (default: 1)

• CHARACTER – same(ANSI)

• VARCHAR2 – max 4000 chars

• NCHAR

• NVARCHAR

• LONG – Up To 2GB

More datatypesMore datatypes

• LONG RAW – 2GB – binary

• RAW – binary – 2000 bytes

• CLOB – char large object(same as LONG)

• NCLOB – unicode

• BLOB – binary large object

• BFILE – file pointer

• DATE

• LONG RAW – 2GB – binary

• RAW – binary – 2000 bytes

• CLOB – char large object(same as LONG)

• NCLOB – unicode

• BLOB – binary large object

• BFILE – file pointer

• DATE

VariablesVariables

DECLARE

my_variable NUMBER(4);

my_second_var NUMBER(4):=22;

my_variable:=77;

DECLARE

my_variable NUMBER(4);

my_second_var NUMBER(4):=22;

my_variable:=77;

SELECT INTOSELECT INTO

DECLAREmy_variable NUMBER(4);my_second_var NUMBER(4);

BEGINmy_variable := 100;SELECT unit_priceINTO my_second_varFROM productWHERE product_id = 50;Dbms_output.Put_line(my_variable);Dbms_output.Put_line('The unit price is: ' || my_second_var);

END;

DECLAREmy_variable NUMBER(4);my_second_var NUMBER(4);

BEGINmy_variable := 100;SELECT unit_priceINTO my_second_varFROM productWHERE product_id = 50;Dbms_output.Put_line(my_variable);Dbms_output.Put_line('The unit price is: ' || my_second_var);

END;

Scope of VariablesScope of Variables

DECLAREv1 NUMBER;v2 NUMBER;/********************The new block begins ....*******************/

BEGINv1 := 100;v2 := 200;DECLARE

v3 NUMBER;BEGIN

v3 := v2 + v1;END;--v3 cannot be accessed FROM here

END;

DECLAREv1 NUMBER;v2 NUMBER;/********************The new block begins ....*******************/

BEGINv1 := 100;v2 := 200;DECLARE

v3 NUMBER;BEGIN

v3 := v2 + v1;END;--v3 cannot be accessed FROM here

END;

ConstantsConstants

DECLAREc_new_sal CONSTANT NUMBER (4) := 500;v_current_sal NUMBER(9,2);

BEGINSELECT salaryINTO v_current_salFROM sales_personWHERE sales_person_id = 804;Dbms_output.Put_line ('Current salary: ' || v_current_sal);v_current_sal := v_current_sal + c_new_sal;Dbms_output.Put_line ('New salary: ' || v_current_sal);

END;

DECLAREc_new_sal CONSTANT NUMBER (4) := 500;v_current_sal NUMBER(9,2);

BEGINSELECT salaryINTO v_current_salFROM sales_personWHERE sales_person_id = 804;Dbms_output.Put_line ('Current salary: ' || v_current_sal);v_current_sal := v_current_sal + c_new_sal;Dbms_output.Put_line ('New salary: ' || v_current_sal);

END;

RecordsRecords

DECLARE

TYPE product_type IS RECORD

(f_product_id NUMBER(5),

f_product_name VARCHAR2(25),

f_supplier_name product.supplier_name%type,

f_unit_price product.unit_price%type);

product_rec product_type;

DECLARE

TYPE product_type IS RECORD

(f_product_id NUMBER(5),

f_product_name VARCHAR2(25),

f_supplier_name product.supplier_name%type,

f_unit_price product.unit_price%type);

product_rec product_type;

ROWTYPEROWTYPE

record_name table_name%ROWTYPE;

Example:

DECLARE

product_rec product%ROWTYPE;

record_name table_name%ROWTYPE;

Example:

DECLARE

product_rec product%ROWTYPE;

Passing ValuesPassing Values

• record_name.field_name := value;• If you used %ROWTYPE:

record_name.col_name := value;

• SELECT col1, col2 INTO record_name.field_name1, record_name.field_name2[WHERE clause];

• If you use %ROWTYPE:SELECT * INTO record_name FROM table_name [WHERE clause];

• record_name.field_name := value;• If you used %ROWTYPE:

record_name.col_name := value;

• SELECT col1, col2 INTO record_name.field_name1, record_name.field_name2[WHERE clause];

• If you use %ROWTYPE:SELECT * INTO record_name FROM table_name [WHERE clause];

%type example%type example

DECLAREcomp_name customer.company_name%type;cont customer.contact_name%type;

BEGINSELECT company_name, contact_nameINTO comp_name,contFROM customerWHERE customer_id = 300;Dbms_output.Put_line ('company: '|| comp_name);Dbms_output.Put_line ('contact: '||cont);

END;

DECLAREcomp_name customer.company_name%type;cont customer.contact_name%type;

BEGINSELECT company_name, contact_nameINTO comp_name,contFROM customerWHERE customer_id = 300;Dbms_output.Put_line ('company: '|| comp_name);Dbms_output.Put_line ('contact: '||cont);

END;

RECORD exampleRECORD example

DECLARETYPE cust_type IS RECORD(

comp_name customer.company_name%type,cont customer.contact_name%type);

cust_rec cust_type;BEGIN

SELECT company_name, contact_nameINTO cust_recFROM customerWHERE customer_id = 300;Dbms_output.Put_line ('company: '|| cust_rec.comp_name);Dbms_output.Put_line ('contact: '|| cust_rec.cont);

END;

DECLARETYPE cust_type IS RECORD(

comp_name customer.company_name%type,cont customer.contact_name%type);

cust_rec cust_type;BEGIN

SELECT company_name, contact_nameINTO cust_recFROM customerWHERE customer_id = 300;Dbms_output.Put_line ('company: '|| cust_rec.comp_name);Dbms_output.Put_line ('contact: '|| cust_rec.cont);

END;

ROWTYPEROWTYPE

DECLAREcust_rec customer%ROWTYPE;

BEGINSELECT *INTO cust_recFROM customerWHERE customer_id = 300;Dbms_output.Put_line ('company: '|| cust_rec.company_name);Dbms_output.Put_line ('contact: '|| cust_rec.contact_name);

END;

DECLAREcust_rec customer%ROWTYPE;

BEGINSELECT *INTO cust_recFROM customerWHERE customer_id = 300;Dbms_output.Put_line ('company: '|| cust_rec.company_name);Dbms_output.Put_line ('contact: '|| cust_rec.contact_name);

END;

Manipulating DataManipulating Data

DECLAREprod_rec product%ROWTYPE;

BEGININSERT INTO productVALUES (100, 'CD', 'American Suppliers', 19.99);SELECT *INTO prod_recFROM productWHERE product_id = 100;Dbms_output.Put_line (prod_rec.product_id);Dbms_output.Put_line (prod_rec.product_name);Dbms_output.Put_line (prod_rec.supplier_name);Dbms_output.Put_line (prod_rec.unit_price);COMMIT;

END;

DECLAREprod_rec product%ROWTYPE;

BEGININSERT INTO productVALUES (100, 'CD', 'American Suppliers', 19.99);SELECT *INTO prod_recFROM productWHERE product_id = 100;Dbms_output.Put_line (prod_rec.product_id);Dbms_output.Put_line (prod_rec.product_name);Dbms_output.Put_line (prod_rec.supplier_name);Dbms_output.Put_line (prod_rec.unit_price);COMMIT;

END;