Description:
Alter one or more fields in an entity table.
Syntax:
T.alter(F:x,…;F’,…)
Note:
The function, supported only when a table is of columnar storage, adds a field F to entity table/multizone entity table T and deletes an old field F’. Values of the new field are obtained by calculating expression x and populated to the table. The dimension and sorting field before it must not be modified.
Parameter:
T |
An entity table/multizone entity table |
F |
Name of the to-be-added field |
x |
An expression |
F’ |
An existing field |
Return value:
An entity table/multizone entity table
Example:
|
A |
|
1 |
=file("emp.ctx") |
An existing composite table file. |
2 |
=A1.open() |
Open the composite table’s base table. |
3 |
=A2.cursor().fetch() |
Query data in the base table. |
4 |
=A2.alter(NEW_Salary:SALARY+1000;GENDER) |
Add NEW_Salary field to the base table through calculating expression SALARY+1000, and delete existing field GENDER. |
5 |
=A2.cursor().fetch() |
Check the base table and we can see that the new field is added and GENDER field is deleted. |