Haskell Language Learning Note (HDBC)

Installing Hdbc-sqlite3

$ cabal install HDBC-Sqlite3Installed HDBC-sqlite3-2.3.3.1Prelude> :m Database.HDBC Database.HDBC.Sqlite3Prelude Database.HDBC Database.HDBC.Sqlite3>

DB operation

Prelude DATABASE.HDBC database.hdbc.sqlite3> Conn <-connectSqlite3 "Test1.db"--connect or create a database Prelude DATABASE.HDBC Database.hdbc.sqlite3> Run Conn "CREATE table Test (ID INTEGER not NULL, desc VARCHAR (80))" []--Build table 0Prelude Database.H DBC database.hdbc.sqlite3> Run conn "INSERT into Test (ID) VALUES (0)" []--insert record 1Prelude DATABASE.HDBC Database.hdbc.s Qlite3> commit Connprelude DATABASE.HDBC database.hdbc.sqlite3> run conn "INSERT into Test VALUES (?,?)" [Tosql 0, Tosql "Zero"]--insert record, use parameter 1Prelude database.hdbc database.hdbc.sqlite3> commit connprelude database.hdbc Dat Abase. Hdbc. sqlite3> stmt <-Prepare conn "INSERT into Test VALUES (?,?)"--insert record, use statement Prelude Database.hdbc Database.HDBC.Sqlit e3> Execute stmt [tosql 1, Tosql "one"] 1Prelude database.hdbc database.hdbc.sqlite3> execute stmt [Tosql 2, Tosql] Both "] 1Prelude database.hdbc database.hdbc.sqlite3> execute stmt [tosql 3, Tosql" three "]1prelude Database.hdbc Databa Se. Hdbc. Sqlite3> Execute STMT [Tosql 4, Sqlnull]1prelude database.hdbc database.hdbc.sqlite3> commit connprelude DATABASE.HDBC database.hdbc.sqlite3> stmt <-Prepare conn "INSERT into Test VALUES (?,?)" Prelude database.hdbc database.hdbc.sqlite3> executemany stmt [[Tosql 5, Tosql ' five ' nice '], [Tosql 6, Sqlnull]]--Plug into multiple records, using statements Prelude Database.hdbc database.hdbc.sqlite3> commit Connprelude database.hdbc database.hdbc.sqlite3> Quickquery ' conn ' select * from Test where ID < 2 "[]--Query record [[SqlInt64 0,sqlnull],[sqlint64 0,sqlbytestring ' zero '],[s QlInt64 1,sqlbytestring "One"]]prelude database.hdbc database.hdbc.sqlite3> quickquery ' conn ' select ID, desc from tes t where ID <=? ORDER by ID, desc "[Tosql 2]--querying records, using parameters [[SqlInt64 0,sqlnull],[sqlint64 0,sqlbytestring" Zero "],[sqlint64 1,sqlbytestrin G "One"],[sqlint64 2,sqlbytestring "]]prelude database.hdbc database.hdbc.sqlite3> stmt <-Prepare conn" SELECT * FROM Test where ID < 2 "--query record Prelude Database.hdbc database.hdbc.sqlite3> Execute stmt []0prelude database.hdbc database.hdbc.sqlite3> results <-fetchallrowsal stmt--Lazy Read PR Elude Database.hdbc database.hdbc.sqlite3> mapm_ print results[("id", SqlInt64 0), ("desc", Sqlnull) [("id", SqlInt64 0), ("desc", sqlbytestring "Zero") [("id", SqlInt64 1), ("desc", sqlbytestring "one")]

DB Operation 2

Prelude Database.HDBC Database.HDBC.Sqlite3> getTables conn["test"]Prelude Database.HDBC Database.HDBC.Sqlite3> proxiedClientName conn"sqlite3"Prelude Database.HDBC Database.HDBC.Sqlite3> dbServerVer conn"3.19.3"Prelude Database.HDBC Database.HDBC.Sqlite3> dbTransactionSupport connTruePrelude Database.HDBC Database.HDBC.Sqlite3> quickQuery' conn "SELECT * from test2" []*** Exception: SqlError {seState = "", seNativeError = 1, seErrorMsg = "prepare 20: SELECT * from test2: no such table: test2"}Prelude Database.HDBC Database.HDBC.Sqlite3> handleSqlError $ quickQuery' conn "SELECT * from test2" []*** Exception: user error (SQL error: SqlError {seState = "", seNativeError = 1, seErrorMsg = "prepare 20: SELECT * from test2: no such table: test2"})Prelude Database.HDBC Database.HDBC.Sqlite3> disconnect conn

Haskell Language Learning Note (HDBC)