Access: How to find a field in a whole database? - database

Question

I have an access database with many tables. I am looking for a field which may or may not exist in one or many of the tables. How do I check if it exists or not? (without querying each table of course)

Answer 1

There is a schema for fields:
Set cn = CurrentProject.Connection
SelectFieldName = "SomeFieldName"
'Get names of all tables that have a column = SelectFieldName '
Set rs = cn.OpenSchema(adSchemaColumns, _
Array(Empty, Empty, Empty, SelectFieldName))
From: MS Access: How to bypass/suppress an error?

Answer 2

If you really do not want to open any table, a solution is to use the tabledefs collection of the database object. Each tabledef item has its own fields collection that you can browse. It would give something like that:
Public function findFieldInDatabase(p_myFieldName)
dim db as database, _
tb as tabledef, _
fd as field
set db = currentDb
for each tb in db.tabledefs
for each fd in tb.fields
if fd.name = p_myFieldName then
debug.print tb.name, fd.name
end if
next fd
next tb
set fd = nothing
set tb = nothing
set db = nothing
end function
This code could be easily adapted to accept an optional p_myTableName as an argument to limit the search to a table/range of tables.

Answer 3

Here's what I would do if I wanted to see if a particular column (identified in strSearch) in a particular table.
Public Sub search()
Dim db As Database
Dim strSearch As String
Dim strSQL As String
Dim rsResults As Recordset
Dim i As Integer
Dim cols As Integer
strSearch = "a3"
Set db = CurrentDb
strSQL = "select * from bar"
Set rsResults = db.OpenRecordset(strSQL, dbOpenDynaset, dbReadOnly)
If Not rsResults.BOF Then
rsResults.MoveFirst
End If
cols = rsResults.Fields.Count - 1 ' -1 because we start counting cols at 0
For i = 0 To cols
If rsResults(i).Name = strSearch Then
MsgBox "Found the seach string"
End If
Next
MsgBox "end of script"
End Sub
Now I know you don't want to write one of those for each table. So the next thing to do would be to loop through all the tables. You can find a list of all the tables with the following SQL
SELECT
name
FROM
MSysObjects
WHERE
(Left([Name],1)<>"~")
AND (Left([Name],4) <> "MSys")
AND ([Type] In (1, 4, 6))
Connecting these two pieces up together, I'll leave as an exercise for the student :)

Answer 4

Here's how you access the table schema in MS Access using VBScript:
TestData = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=c:\somefolder\YOURDB.mdb"
Set Conn = Server.CreateObject("ADODB.Connection")
Conn.Open TestData
Set rs = Conn.OpenSchema(4)
do until Rs.eof
tn = RS("TABLE_NAME")
fn = RS("COLUMN_NAME")
' your script goes here
loop

Answer 5

Here you go:
Public Function fTableExists(ByVal vstrTable As String) As Boolean
Dim rs As ADODB.Recordset
Set rs = CurrentProject.Connection.OpenSchema( _
adschematables, Array(Empty, Empty, vstrTable))
fTableExists = Not rs.EOF
rs.Close
Set rs = Nothing
End Function
Public Function fColumnExists(ByVal vstrTable As String, _
ByVal vstrColumn As String) As Boolean
Dim rs As ADODB.Recordset
Set rs = CurrentProject.Connection.OpenSchema(adSchemaColumns, _
Array(Empty, Empty, vstrTable, vstrColumn))
fColumnExists = Not rs.EOF
rs.Close
Set rs = Nothing
End Function

Answer 6

MSSQL
Looking for ADDRESS1 column:
select so.name from sysobjects so
where so.id in (select sc.id from syscolumns sc where name like 'ADDRESS1')
ORACLE
http://en.wikipedia.org/wiki/Oracle_metadata
Google will find the syntax for other DBs...

Answer 7

What type of database is it? If it's SQL Server you can try this:
SELECT * FROM sysobjects WHERE xtype = 'U' AND name = 'myTable'
But since it's the column you're looking for and not a table (thanks Brian), try this:
SELECT
DISTINCT
so.[name] AS 'Table',
sc.[name] AS 'Column'
FROM
syscolumns sc
JOIN
sysobjects so
ON
so.id = sc.id
WHERE
sc.[name] = 'myTable'