Delphi getting Oracle error ORA-12899 Error value too large for the column

I have a database in Oracle. The client application is written in Delphi. When I enter values into the DBGrid which is connected to a table in the database I get "ORA-12899 Error value too large for the column".The datatype of the column specified in the error message is varchar(6).And I exactly enter 6 digits.The error also indicates that the maximum is 6 the actual is 7 which is wrong.I 开发者_JAVA百科tried changing the datatype to number but I get the same error with just a difference that it say maximum is 3 the actual is 4.Is there a bug with Delphi and Oracle? I use ADO for connection.There's notthing in the BeforePost event.

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Not knowing anything at all about Delphi, could it be that your grid data cell is interpreted as a number and a space is being reserved for the sign?

EDIT:

What happens if you type 6 characters but include 1 or more alphas?