SQL Server does not normally define parameter objects and provides inconsistent or incomplete information.

This error is generated when a query statement is executed:

With dm. ADOQuery1 do
Begin
Close;
SQL. Clear;
SQL. Add ('select hyxx. *, hyjbxx. jbmc from hyxx, hyjbxx where hyxx. jb = hyjbxx. jbid'); Open;
End;

Copy the SQL statement to the query analyzer for execution. According to past experience, the first reason for this error is that the connection is not connected, the second is that the query statement contains a colon, but the paramcheck of adoquery is true. I have checked these two reasons and none of them exist. I connected another database with the same structure, and there was no running problem, that is, there was a problem with the records in the table. The ID (primary key) of the first data in the hyxx table is empty. I was wondering where the empty string came from. The original program did not control the empty string? Don't look for the cause first. Check if this is the cause first. Fill in a few characters, save, execute the program, OK!