Hi there.
i'm having trouble joining tables. I'm using Access database. Initially, i have 2 tables called thresholdTable and Configuration. In the thresholdTable, there's a column called 'Config' and i've linked it to a column called 'Confuguration' from the Configuration table. Right now everything's working. However, i added another table, Consistency. I have a column in thresholdTable called 'Consistency' and i have to link it to 'Consistency' column from the Consistency table. How do i join 3 tables? Here's my codes:

Dim con As New OleDb.OleDbConnection
Dim ds As New DataSet
Dim da As New OleDb.OleDbDataAdapter
Dim sql As String

con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Sowmya.mdb;Jet OLEDB:Database Password=geez"


con.Open()

sql = "SELECT * FROM thresholdTable INNER JOIN Configuration ON Configuration.Configuration = thresholdTable.Config"
da = New OleDb.OleDbDataAdapter(sql, con)
da.Fill(ds, "Sowmya")


con.Close()

You can chain joins together and the next join works on the result of the last join.
The intermediate table that you join Consistency to is the result of joining thresholdTable and Configuration. If you wrap it in parentheses it's like this guy.

I tried chain joins them together but i get an error. It says "Syntax error (missing operator) in query expression 'Configuration.Configuration = thresholdTable.Config INNER JOIN consistency ON consistency.consistency = thresholdTable.Consistency"

Hi,

check this:


Regards
Veena

Then what about the consistency table? I also need to link the 'Consistency' column from thresholdTable to 'consistency' column from consistency table.

Hi,

Then give one more condition in where:


u can give any number of equal conditions..

Regards
Veena

Hi,

In case u have one more table, include that also in SQL Statement and give appropriate links..

Regards
Veena

Hi..
I'm still facing some errors. It says No value given for one or more required parameters. By the way, my 'consistency' column is not from Configuration table. It's from another table called consistency. So actually i have 3 tables, thresholdTable, Configuration and consistency.

The relationship is like this:
Configuration.Configuration = thresholdTable.config,
consistency.consistency = thresholdTable.Consistency

Hi,

Post the whole SQL Statement here. Such error occur when u have Mis-Spelled the Column Or Table Name.
I noticed it now Remove the Comma in the Relationship and give AND there. Check This:

Hi..
i'm still having errors. I added this statement:

sql = "SELECT * FROM thresholdTable Where Configuration.Configuration = thresholdTable.config And consistency.consistency = thresholdTable.Consistency"

It highlighted this code and says that no value is given for one or more required parameters.

Me.ThresholdTableTableAdapter.Fill(Me.SowmyaDataSet.thresholdTable)