Difference between revisions of "Cookbook/Databases access"
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There are two packages you can use to connect to MySQL, PostgreSQL, Sqlite3 and ODBC databases: [http://software.complete.org/software/projects/show/hdbc HDBC] and Hsql |
There are two packages you can use to connect to MySQL, PostgreSQL, Sqlite3 and ODBC databases: [http://software.complete.org/software/projects/show/hdbc HDBC] and Hsql |
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− | = MySQL = |
+ | == MySQL == |
TODO |
TODO |
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− | = PostgreSQL = |
+ | == PostgreSQL == |
TODO |
TODO |
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− | = SQLite = |
+ | == SQLite == |
Suppose you have created a 'test.db' database like this, |
Suppose you have created a 'test.db' database like this, |
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Revision as of 11:33, 9 July 2009
There are two packages you can use to connect to MySQL, PostgreSQL, Sqlite3 and ODBC databases: HDBC and Hsql
MySQL
TODO
PostgreSQL
TODO
SQLite
Suppose you have created a 'test.db' database like this,
$ sqlite3 test.db "create table t1 (t1key INTEGER PRIMARY KEY,data TEXT,num double,timeEnter DATE);"
$ sqlite3 test.db "insert into t1 (data,num) values ('This is sample data',3);"
$ sqlite3 test.db "insert into t1 (data,num) values ('More sample data',6);"
$ sqlite3 test.db "insert into t1 (data,num) values ('And a little more',9);"
Using HDBC and HDBC-sqlite3 packages, you can connect and query it like this:
import Control.Monad
import Database.HDBC
import Database.HDBC.Sqlite3
main = do conn <- connectSqlite3 "test.db"
rows <- quickQuery' conn "SELECT * from t1" []
forM_ rows $ \row -> putStrLn $ show row
$ ghc --make sqlite.hs
$ ./sqlite
output:
[SqlString "1",SqlString "This is sample data",SqlString "3.0",SqlNull]
[SqlString "2",SqlString "More sample data",SqlString "6.0",SqlNull]
[SqlString "3",SqlString "And a little more",SqlString "9.0",SqlNull]