How to change datatype of column in Sybase?

Posted on by David Darling

How to change datatype of column in Sybase?

Use alter table to modify an existing column. You can modify any number of columns in a single alter table statement. Warning! You may have objects (stored procedures, triggers, and so on) that depend on a column having a particular datatype.

How to alter table in Sybase?

Syntax

  1. alter table syntax for partitions:
  2. alter table syntax for computed columns alter table add column_name {compute | as} computed_column_expression… [
  3. alter table syntax for dropping partitions alter table table_name drop partition partition_name [, partition_name]…

How do you modify a column of data in SQL?

To change the data type of a column in a table, use the following syntax:

  1. SQL Server / MS Access: ALTER TABLE table_name. ALTER COLUMN column_name datatype;
  2. My SQL / Oracle (prior version 10G): ALTER TABLE table_name. MODIFY COLUMN column_name datatype;
  3. Oracle 10G and later: ALTER TABLE table_name.

How do I rename a column in Sybase?

Usage

  1. sp_rename changes the name of a user-created object or datatype.
  2. When you are renaming a column or index, do not specify the table name in newname.
  3. If a column and an index have the same name, use the [,“index” | “column”] argument, which specifies whether to rename the index or the column.

How do I find the maximum length of a column in Sybase?

Use the char_length string function and datalength system function to determine column length:

  1. char_length returns the number of characters in the column, stripping trailing blanks for variable-length datatypes.
  2. datalength returns the number of bytes, stripping trailing blanks for data stored in variable-length columns.

How do I change primary key in Sybase?

Configure a primary key using Sybase Central

  1. Connect to the database using the SQL Anywhere 12 plug-in.
  2. In the left pane, double-click Tables.
  3. Right-click the table and click Set Primary Key.
  4. Follow the instructions in the Set Primary Key Wizard.

How do I drop a column in Sybase?

You can delete columns by selecting the column on the Columns tab and choosing File > Remove Column. You can copy a column to a table by selecting the column on the Columns tab in the right pane and then clicking the Copy button.

How do I change the field type without dropping the table?

So to do that go to SQL Server and within Tools select Options. Now in the option window expand Designers and under that “Table and Database Designers” and uncheck the check box “Prevent saving changes that require table re-creation” then click OK.

How get datatype of a column in SQL?

You can get the MySQL table columns data type with the help of “information_schema. columns”. SELECT DATA_TYPE from INFORMATION_SCHEMA. COLUMNS where table_schema = ‘yourDatabaseName’ and table_name = ‘yourTableName’.

How do you change a column name?

To change a column name, enter the following statement in your MySQL shell: ALTER TABLE table_name RENAME COLUMN old_column_name TO new_column_name; Replace table_name , old_column_name , and new_column_name with your table and column names.

How do you change the datatype of a primary key column in SQL?

Using Microsoft SQL Server Management Studio do the following:

  1. Open table Design.
  2. Change the primary key column type or any other change which is also possible with this way.
  3. Right click on the design area and select Generate Change Script.
  4. Accept Validation Warning.
  5. Preview changes or save them in file.
  6. Profit 🙂

Can we update the primary key column in a table?

Because a table can have only one primary key, you cannot add a primary key to a table that already has a primary key defined. To change the primary key of a table, delete the existing key using a DROP clause in an ALTER TABLE statement and add the new primary key.

How do I drop a column in a table?

Syntax. The syntax to drop a column in a table in MySQL (using the ALTER TABLE statement) is: ALTER TABLE table_name DROP COLUMN column_name; table_name.

Can we drop column in table?

SQL allows a user to remove one or more columns from a given table in the database if they are no longer needed or become redundant. To do so, the user must have ALTER permission on the object. Let’s begin with the syntax for using the ALTER TABLE DROP COLUMN statement.

How do I change the datatype of a column in SQL without dropping the table?

How do I convert VARCHAR to int in SQL?

SQL Server’s CAST() and CONVERT() methods can be used to convert VARCHAR to INT….TRY_CONVERT()

  1. data_type: Valid data type into which the function will cast the expression.
  2. expression: Value to be cast.
  3. style: Is a provided integer that specifies how the function will translate the expression.

How do I rename a column in SQL?

Select and right-click on a table or a column you want to rename and click Rename. Enter a new name by over writing on existing name. Go to the file menu and click Save.