"Read DataBase

Question

Hi,
I know the operator Read DataBase can build sql query and I can get the right answer.
I also find the opertaor Execute SQL can also build sql query,but I can not get the right answer when I write a simple select query.
Can you tell me how to use the operator Execute SQL  and what's the difference between these two operators.
Thank you!

haddock · Answer

I was quoting from the help. !!This operator performs an arbitrary SQL statement on an SQL database. The SQL query can be passed to RapidMiner via a parameter or, in case of long SQL statements, in a separate file. Please note that column names are often case sensitive. Databases may behave differently here.
Please note that this operator cannot be used to load data from databases but mereley to execute SQL statements like CREATE or ADD etc. In oder to load data from a database, the operators DatabaseExampleSource or CachedDatabaseExampleSource can be used.

land · Answer

Hi,
as a side note: The two operators referenced by Haddock are now called "Read Database" or "Stream Database" in RapidMiner 5.0.

Greetings,
  Sebastian

haddock · Answer

Hi there,

The  "Execute SQL" operator cannot be used to load data from databases but mereley to execute SQL statements like CREATE or ADD etc. In oder to load data from a database, the operators DatabaseExampleSource or CachedDatabaseExampleSource can be used.