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10 Απρ 2017 · The data type of columns included in an index cannot be changed unless the column is a varchar, nvarchar, or varbinary data type, and the new size is equal to or larger than the old size. Otherwise you would drop the index(es), alter the column, then add back the index(es).
Hints that specify an index can use either a simple index name or a parenthesized list of columns as follows: Figure 17-2 Indexspec Syntax. indexspec::= Text description of the illustration indexspec.gif. where: table specifies the name; column specifies the name of a column in the specified table
To change the definition of a column in a table, you use the ALTER TABLE MODIFY column syntax as follows: ALTER TABLE table_name . MODIFY column_name action; Code language: SQL (Structured Query Language) (sql) The statement is straightforward.
Renaming a column using alter table. ALTER TABLE JOBS_Temp RENAME COLUMN COMM TO COMMISSION
To alter an index, your schema must contain the index, or you must have the ALTER ANY INDEX system privilege. With the ALTER INDEX statement, you can: Rebuild or coalesce an existing index
14 Μαΐ 2005 · SQL> -- Rename the table, columns, primary key and supporting index. alter table test1 rename to test; alter table test rename column col1 to id; alter table test rename column col2 to description; alter table test rename constraint test1_pk to test_pk; alter index test1_pk rename to test_pk; -- Describe the table.
12 Νοε 2018 · ALTER TABLE command helps to modify table properties. Similarly, the alter table modify column helps to change column datatype to another datatype. Apart from that, it also helps to set default values, add NULL checks to an existing column. In this Oracle Tutorial, we will go through each possibility as well as it’s syntax. So, let us get into it.
