Uses the Persistent package and HDBC-odbc to access databases via ODBC.
Thanks to Dmitry Olshansky at https://github.com/odr/persistent-odbc/ for doing the initial hookup to hdbc-odbc.
Supports Postgres, MySql, MS Sql Server, Oracle, DB2, and SQLite.
see TestODBC.hs for usage and tests.
git clone https://github.com/gbwey/persistent-odbc
cd persistent-odbc
stack ghci --test --flag persistent-odbc:tester
:load TestODBC.hs (also need to define the appropriate odbc system dsn below and then run the command)
e.g. for postgresql
1. create a system odbc dsn "pg_test"
2. :main p
| DBMS | ODBC System Dsn | Command |
|---|---|---|
| Postgresql | dsn=pg_test | :main p |
| MySQL | dsn=mysql_test | :main m |
| DB2 | dsn=db2_test | :main d |
| Ms Sql Server >= 2012 | dsn=mssql_test | :main s |
| Ms Sql Server pre 2012 | dsn=mssql_test | :main so |
| Oracle pre 12c | dsn=oracle_test | :main o |
| Oracle >= 12c | dsn=oracle_test | :main on |
| Sqlite | dsn=sqlite_test | :main q |
MSSQL True for MS Sql Server 2012 which has limit and offset support (esqueleto as well). MSSQL False for MS Sql Server pre 2012 only supports limit using Persistent's select* operations. (select top n ...).
Oracle True for Oracle >=12c which has limit and offset support (esqueleto as well). Oracle False for Oracle <12c where there is no limit and offset support.
Blobs are problematic in hdbc-odbc.
Can cause segfault in Ms Sql Server.
Treats empty string as a null (oracle issue).
Cannot sort on a blob field (oracle issue).
Blobs don't support nulls (both insert and select) in this version of persistent-odbc (also doesn't work in hdbc-odbc). Select returns the blob values as unpacked strings at the moment (if there is interest in getting this fixed let me know).