How do I handle BIT / BOOLEAN columns?

In Microsoft Access, you can say: 
 

SELECT columns FROM table WHERE boolColumn=TRUE  -- or  SELECT columns FROM table WHERE boolColumn=FALSE

 
Unfortunately, this doesn't work in SQL Server. The following can be used in SQL Server: 
 

SELECT columns FROM table WHERE bitColumn=1  -- or  SELECT columns FROM table WHERE bitColumn=0

 
However, this doesn't work in Access, since TRUE in Access is -1, not 1. Confused yet? :-) 
 
For cross-platform support, use the following queries: 
 

SELECT columns FROM table WHERE bitColumn<>0  -- or  SELECT columns FROM table WHERE bitColumn=0    -- to update (Access will convert to -1):  UPDATE table SET bitColumn=1  --or  UPDATE table SET bitColumn=0

 
Also, remember that if you're using checkboxes to update / insert / display data, you have to convert from "on" or "" to 1 or 0, and when retrieving you must change 1 or 0 (or true or false) to "checked"... for example, page1.asp: 
 

<form method=post action=page2.asp>  <input type=checkbox name=bool>  <input type=submit>  </form>

 
And page2.asp: 
 

<%      bitValue = 0      bool = request.form("bool")      if bool = "on" then bitValue=1      sql = "UPDATE table SET bitColumn=" & bitValue      ' ...  %>

 
And page3.asp: 
 

<%      set conn = CreateObject("ADODB.Connection")      conn.open "<connection string>"      set rs = conn.execute("SELECT bitColumn FROM table")      ch=""      bitValue = rs(0)      if bitValue then ch=" CHECKED"      ' or you could say if bitValue<>0 then ch=" CHECKED"  %>  <form method=post action=page2.asp>  <input type=checkbox name=bool <%=checked%>>  <input type=submit>  </form>