“date” as a column name

问题:

I have a table called calendars.

One of its columns is named 'date'

When I want to select the date column it gives error ORA-01747 namely invalid table.column.

select date from calendars

I guess this happens because 'date' is a reserved word for pl/sql. The problem is it's not even possible to change the column name :

alter table calendars rename column date to date_d

Result is: ORA-00904 error: invalid identifier.

What do you advice?

Thanks.

回答1:

Have you tried

select calendars.date from calendars; /* or you could alias "calendars" if you don't want to type so much */

If that doesn't work or help, have you tried dropping the column (and maybe try referencing it with the table name prefix: calendars.date)?

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I also found this post: How do I escape a reserved word in Oracle?

It seems that Oracle will be case-sensitive if you use double quotes so

select "date" from calendars;

is not the same as

select "Date" from calendars;

回答2:

Try escaping the reserved word with double quotes.

select "date" from calendars

回答3:

date is a reserved keyword and hence cannot be used like

SELECT date from some table

there can be multiple solutions for the problem

• The date column needs to be enclosed within the brackets like

SELECT [date] FROM tableName

• Enclose the reserved keyword in backticks

SELECT 'date' from tableName

• Use alias

SELECT tableName.date from tableName