两个表A和B都有<代码>id=1111(显示)。 如果我们做到:
select A.* from A where id= 1111
以及
select B.* from B where id= 1111
他们都取得了回报。 当我们做时:
select A. * , B. * from A, B where A.id=B.id 以及 A.id= 1111
它没有回报。 为什么?
两个表A和B都有<代码>id=1111(显示)。 如果我们做到:
select A.* from A where id= 1111
以及
select B.* from B where id= 1111
他们都取得了回报。 当我们做时:
select A. * , B. * from A, B where A.id=B.id 以及 A.id= 1111
它没有回报。 为什么?
select A.* , B.* from A inner join B ON A.id=B.id where A.id= 1111
I m trying to export some tables from SQL Server 2005 and then create those tables and populate them in Oracle. I have about 10 tables, varying from 4 columns up to 25. I m not using any constraints/...
I ve got the following objects: CREATE FUNCTION CONSTFUNC RETURN INT DETERMINISTIC AS BEGIN RETURN 1; END; CREATE TABLE "FUNCTABLE" ( "ID" NUMBER(*,0) NOT NULL, "VIRT" NUMBER GENERATED ALWAYS AS ...
The following code works. the connection opens fine but recordset.recordCount always returns -1 when there is data in the table. ANd If I try to call any methods/properties on recordset it crashes ...
I was wondering, is there a way to make a kind of one to one left outer join: I need a join that matches say table A with table B, for each record on table A it must search for its pair on table B, ...
I need to be able to run an Oracle query which goes to insert a number of rows, but it also checks to see if a primary key exists and if it does, then it skips that insert. Something like: INSERT ALL ...
I just came across NULL values in NOT-NULL fields in our test database. How could they get there? I know that NOT-NULL constraints can be altered with NOVALIDATE clause, but that would change table s ...
I m studying databases and am currently working on a object-relational DB project and I ve encountered a small problem with the number of possible constraints in an object table. I m using "Database ...
we have a table in an Oracle Database which contains a column with the type Char(3 Byte). Now we use a parameterized sql to select some rows with a DBNull.Value and it doesn t work: OracleCommand ...