Oracle PL/SQL Syntax basics

Directory

Data type

Defining variables

PL/SQL Control structure

Reference oracle10g data Types Summary PL/SQL basic articles

Data type

Learning Summary

Character type

Char, nchar, varchar, nvarchar: There are n characters stored with no n in bytes storage, VAR is variable, storage space is stored in the actual size, no var is fixed size, from the space to be padded.

Number Type

Number (P[,s]): Fixed-point numbers, S is the number of decimal digits

Binary_float:32 bit single-precision floating-point number type

binary_double:64-bit double-precision floating-point number type.

Time Type

Date

Defining variables

Resources

Oracle User Manual (i)---declaring variables

You can use: = To assign values when defining variables

1. Define BASIC variables

Such as: Declare variable name variable type

2. Define%type with attributes

Can be a property of a table field or variable

declare name Tablename.fieldname%type;

DECLARE name2 Name%type

3, using%rowtype, define the variable is a row of the table

Delcare Row Tablename%rowtype

4. Define record type variables-record data types that bundle multiple base data types together.

Syntax: Type record name is record (definition base type)

Set Serveroutput on
Declare
Type Myrecord is record (
Sid Int,
Sdate date);
Srecord Myrecord; --Declare an instance of a custom record type variable
Begin
Select Sid,sdate into Srecord from student where sid=68;
Dbms_output.put_line (' ID: ' | | srecord.sid | | '  Date: ' | | Srecord.sdate); --' | | ': It is a string connector.
End

5. Table Type variables

Grammar:

TYPE table_name is table of data_type [not NULL]
INDEX by Binary_integer;
The syntax is described as follows:
--table_name the name of the table type created.
The--is table indicates that a table type was created.
--data_type can be any of the legitimate PL/SQL data types, such as VARCHAR2.
--index by Binary_integer Specifies that the system creates a primary key index that refers to a specific row in a table-type variable.

Declare a table with only one field:

Declare

Type Tabletype1 is Table of VARCHAR2 (4) index by Binary_integer;

Mytable1 Tabletype1

A table that declares multiple fields

Declare
Type Tabletype1 is table of Student%rowtype index by Binary_integer;
Table1 Tabletype1;

Type tabletype2 is table of record type variable index by Binary_integer

Table2 taabletype2

DECLARENumber (7, 2): = 1234.33;--Initial value         Field1 tablename.fieldname%type-- field2 field1% type declared with table field     -- declare with variable attributes

PL/SQL Control structure

1. If

Oracle PL/SQL Syntax basics