Documentation

Fields

• runStmt :: Text -> [Param] -> IO (Int, [[SqlValue]])

  Execute an SQL statement.

• runStmtWithPK :: Text -> [Param] -> IO Int

  Execute an SQL statement and return the last inserted primary key, where the primary key is auto-incrementing. Backends must take special care to make this thread-safe.

• prepareStmt :: StmtID -> [SqlTypeRep] -> Text -> IO Dynamic

  Prepare a statement using the given statement identifier.

• runPrepared :: Dynamic -> [Param] -> IO (Int, [[SqlValue]])

  Execute a prepared statement.

• getTableInfo :: TableName -> IO [ColumnInfo]

  Get a list of all columns in the given table, with the type and any modifiers for each column. Return an empty list if the given table does not exist.

• ppConfig :: PPConfig

  SQL pretty-printer configuration.

• closeConnection :: SeldaConnection -> IO ()

  Close the currently open connection.

• backendId :: BackendID

  Unique identifier for this backend.

• disableForeignKeys :: Bool -> IO ()

  Turn on or off foreign key checking, and initiate/commit a transaction.

  When implementing this function, it is safe to assume that disableForeignKeys True will always be called exactly once before each disableForeignKeys False.

Fields

• ppType :: SqlTypeRep -> Text

  The SQL type name of the given type.

  This function should be used everywhere a type is needed to be printed but in primary keys position. This is due to the fact that some backends might have a special representation of primary keys (using sequences are such). If you have such a need, please use the ppTypePK record instead.

• ppTypeHook :: SqlTypeRep -> [ColAttr] -> (SqlTypeRep -> Text) -> Text

  Hook that allows you to modify ppType output.

• ppTypePK :: SqlTypeRep -> Text

  The SQL type name of the given type for primary keys uses.

• ppPlaceholder :: Int -> Text

  Parameter placeholder for the nth parameter.

• ppColAttrs :: [ColAttr] -> Text

  List of column attributes.

• ppColAttrsHook :: SqlTypeRep -> [ColAttr] -> ([ColAttr] -> Text) -> Text

  Hook that allows you to modify ppColAttrs output.

• ppAutoIncInsert :: Text

  The value used for the next value for an auto-incrementing column. For instance, DEFAULT for PostgreSQL, and NULL for SQLite.

• ppMaxInsertParams :: Maybe Int

  Insert queries may have at most this many parameters; if an insertion has more parameters than this, it will be chunked.

  Note that only insertions of multiple rows are chunked. If your table has more than this many columns, you should really rethink your database design.

• ppIndexMethodHook :: IndexMethod -> Text

  CREATE INDEX suffix to indicate that the index should use the given index method.

Fields

• colName :: ColName

  Name of the column.

• colType :: Either Text SqlTypeRep

  Selda type of the column, or the type name given by the database if Selda couldn't make sense of the type.

• colIsPK :: Bool

  Is the given column the primary key of its table?

• colIsAutoIncrement :: Bool

  Is the given column auto-incrementing?

• colIsUnique :: Bool

  Is the column unique, either through a UNIQUE constraint or by virtue of being a primary key?

• colIsNullable :: Bool

  Can the column be NULL?

• colHasIndex :: Bool

  Does the column have an index?

• colFKs :: [(TableName, ColName)]

  Any foreign key (table, column) pairs referenced by this column.