Obtain Field Type

[subscripciones]

I am trying to obtain the data type (logical, character, etc) from a table and field name stored in a variable.

DEFINE VARIABLE columnName AS CHARACTER.
columnName = "TableCustomer.ColumnId".
DEFINE VARIABLE typeResult AS CHARACTER.

...do Something...

DISPLAY typeResult. /* ex. ColumnId Data Type: RECID) */


thanks

 

[DevTeam]

You can achieve it through BUFFER-FIELD attributes :

DEFINE VARIABLE columnName AS CHARACTER.
DEFINE VAR bh AS WIDGET-HANDLE.
DEFINE VARIABLE typeResult AS CHARACTER.

columnName = "myTable.myField".

CREATE BUFFER bh FOR TABLE ENTRY(1, columnName, ".").

typeResult = bh:BUFFER-FIELD(ENTRY(2, columnName, ".")):DATA-TYPE.

DISPLAY typeResult.

 

[TomBascom]

The BUFFER-FIELD trick is clever!

The "classic" method is to lookup _File & _Field:

find _file no-lock where _file-name = "customer".
find _field no-lock where _file-recid = recid( _file ) and _field-name = "name".
display _data-type.

 

[subscripciones]

could not create buffer object for table TableCustomer. (7334)

 

[subscripciones]

DEFINE VARIABLE columnName AS CHARACTER.
DEFINE VAR bh AS WIDGET-HANDLE.
DEFINE VARIABLE typeResult AS CHARACTER.
columnName = "TableCustomer.ColumnId".
CREATE BUFFER bh FOR TABLE ENTRY(1, columnName, ".").
typeResult = bh:BUFFER-FIELD(ENTRY(2, columnName, "."))ATA-TYPE.
DISPLAY typeResult.

Result: could not create buffer object for table TableCustomer. (7334)


----

find _file no-lock where _file-name = "customer".
find _field no-lock where _file-recid = recid( _file ) and _field-name = "name".
display _data-type.

Result:

Unknown or ambiguous table _file. (725)
** Could not understand line 1. (196)


What is _file?


thanks

 

[DevTeam]

could not create buffer object for table TableCustomer. (7334)

What kind of object is TableCustomer ? A physical table ? A Temp-Table ?

 

[DevTeam]

The BUFFER-FIELD trick is clever!

:lol:

Thanks ! However I'm sure it is far slower than querying _file and _file.

 

[subscripciones]

physical table

 

[subscripciones]

find _file no-lock where _file-name = "customer".
find _field no-lock where _file-recid = recid( _file ) and _field-name = "name".
display _data-type.

Forget to create an alias.

this works.



thanks!

 

[TomBascom]

What is _file?

The meta-schema table that describes the tables in your database.

 

[jongpau]

The dynamic method using buffer objects is of course more portable across appserver and client code since it can also be used for fields in temp-tables

Paul