Changing the Precision of a Numeric Column : Alter Table « Table « Oracle PL/SQL Tutorial

SQL>

SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE),
  3    First_Name         VARCHAR2(10 BYTE),
  4    Last_Name          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /

Table created.

SQL>
SQL> desc employee;
 Name                Type
 --------------------
 ID                  VARCHAR2(4)
 FIRST_NAME          VARCHAR2(10)
 LAST_NAME           VARCHAR2(10)
 START_DATE          DATE
 END_DATE            DATE
 SALARY              NUMBER(8,2)
 CITY                VARCHAR2(10)
 DESCRIPTION         VARCHAR2(15)

SQL>
SQL> ALTER TABLE employee
  2  MODIFY salary NUMBER(8,4);

Table altered.

SQL>
SQL> desc employee;
 Name          Type
 --------------
 ID            VARCHAR2(4)
 FIRST_NAME    VARCHAR2(10)
 LAST_NAME     VARCHAR2(10)
 START_DATE    DATE
 END_DATE      DATE
 SALARY        NUMBER(8,4)
 CITY          VARCHAR2(10)
 DESCRIPTION   VARCHAR2(15)

SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /

Table dropped.

SQL>
SQL>

6.3.Alter Table
	6.3.1.	Altering a Table
	6.3.2.	Some of the aspects of a column you can modify using ALTER TABLE
	6.3.3.	Adding a Column
	6.3.4.	ADD initially_created DATE DEFAULT SYSDATE NOT NULL;
	6.3.5.	Changing the Size of a Column
	6.3.6.	Decrease the length of a column
	6.3.7.	Changing the Precision of a Numeric Column
	6.3.8.	Decrease the precision of a numeric column
	6.3.9.	Changing the Data Type of a Column
	6.3.10.	Fill data into new added table column
	6.3.11.	Changing the Default Value of a Column
	6.3.12.	Alter table to add new constraint for new added column
	6.3.13.	ALTER TABLE to DISABLE a CONSTRAINT
	6.3.14.	Alter table to add primary key
	6.3.15.	Alter table to add primary key across more than one columns
	6.3.16.	Dropping a Column
	6.3.17.	New added columns are empty
	6.3.18.	Alter table to add unique with tablespace and storage setting
	6.3.19.	Alter table to add primary key with tablespace and storage setting
	6.3.20.	alter table nologging