odbc

connection_reference() - as returned by connect/2    

time_out() = milliseconds() | infinity    

milliseconds() = integer() >= 0     

common_reason() = connection_closed | extended_error() | term() - some kind of
explanation of what went wrong    

extended_error() = {string(), integer(), Reason} - extended error type with ODBC
and native database error codes, as well as the base reason that would have been
returned had extended_errors not been enabled. 

string() = list of ASCII characters    

col_name() = string() - Name of column in the result set    

col_names() - [col_name()] - e.g. a list of the names of the
          selected columns in the result set.     

row() = {value()} - Tuple of column values e.g. one row of the
          result set.     

value() = null | term() - A column value.     

rows() = [row()] - A list of rows from the result set.    

result_tuple() =
     {updated, n_rows()} | {selected, col_names(), rows()}    

n_rows() = integer() - The number of affected rows for UPDATE,
          INSERT, or DELETE queries. For other query types the value
          is driver defined, and hence should be ignored.    

odbc_data_type() = sql_integer | sql_smallint | sql_tinyint |
     {sql_decimal, precision(), scale()} |
     {sql_numeric, precision(), scale()} |
     {sql_char, size()} |
     {sql_wchar, size()} |
     {sql_varchar, size()} |
     {sql_wvarchar, size()}|
     {sql_float, precision()} |
     {sql_wlongvarchar, size()} |
     {sql_float, precision()} |
     sql_real | sql_double | sql_bit | atom()

precision() = integer()    

scale() = integer()    

size() = integer()    

commit(Ref, CommitMode) ->

commit(Ref, CommitMode, TimeOut) -> ok | {error, Reason}

Types

Commits or rollbacks a transaction. Needed on connections where automatic commit is turned off.

connect(ConnectStr, Options) -> {ok, Ref} | {error, Reason}

Types

An example of a connection string: "DSN=sql-server;UID=aladdin;PWD=sesame" where DSN is your ODBC Data Source Name, UID is a database user id and PWD is the password for that user. These are usually the attributes required in the connection string, but some drivers have other driver specific attributes, for example "DSN=Oracle8;DBQ=gandalf;UID=aladdin;PWD=sesame" where DBQ is your TNSNAMES.ORA entry name e.g. some Oracle specific configuration attribute.

All options has default values.

Opens a connection to the database. The connection is associated with the process that created it and can only be accessed through it. This function may spawn new processes to handle the connection. These processes will terminate if the process that created the connection dies or if you call disconnect/1.

If automatic commit mode is turned on, each query will be considered as an individual transaction and will be automatically committed after it has been executed. If you want more than one query to be part of the same transaction the automatic commit mode should be turned off. Then you will have to call commit/3 explicitly to end a transaction.

The default timeout is infinity

>If the option binary_strings is turned on all strings will be returned as binaries and strings inputed to param_query will be expected to be binaries. The user needs to ensure that the binary is in an encoding that the database expects. By default this option is turned off.

As default result sets are returned as a lists of tuples. The TupleMode option still exists to keep some degree of backwards compatibility. If the option is set to off, result sets will be returned as a lists of lists instead of a lists of tuples.

Scrollable cursors are nice but causes some overhead. For some connections speed might be more important than flexible data access and then you can disable scrollable cursor for a connection, limiting the API but gaining speed.

If trace mode is turned on this tells the ODBC driver to write a trace log to the file SQL.LOG that is placed in the current directory of the erlang emulator. This information may be useful if you suspect there might be a bug in the erlang ODBC application, and it might be relevant for you to send this file to our support. Otherwise you will probably not have much use of this.

The extended_errors option enables extended ODBC error information when an operation fails. Rather than returning {error, Reason}, the failing function will reutrn {error, {ODBCErrorCode, NativeErrorCode, Reason}}. Note that this information is probably of little use when writing database-independent code, but can be of assistance in providing more sophisticated error handling when dealing with a known underlying database.

• ODBCErrorCode is the ODBC error string returned by the ODBC driver.
• NativeErrorCode is the numberic error code returned by the underlying database. The possible values and their meanings are dependent on the database being used.
• Reason is as per the Reason field when extended errors are not enabled.

disconnect(Ref) -> ok | {error, Reason}

Types

Closes a connection to a database. This will also terminate all processes that may have been spawned when the connection was opened. This call will always succeed. If the connection cannot be disconnected gracefully it will be brutally killed. However you may receive an error message as result if you try to disconnect a connection started by another process.

describe_table(Ref, Table) ->

describe_table(Ref, Table, Timeout) -> {ok, Description} | {error, Reason}

Types

Queries the database to find out the ODBC data types of the columns of the table Table.

first(Ref) ->

first(Ref, Timeout) -> {selected, ColNames, Rows} | {error, Reason}

Types

Returns the first row of the result set and positions a cursor at this row.

last(Ref) ->

last(Ref, TimeOut) -> {selected, ColNames, Rows} | {error, Reason}

Types

Returns the last row of the result set and positions a cursor at this row.

next(Ref) ->

next(Ref, TimeOut) -> {selected, ColNames, Rows} | {error, Reason}

Types

Returns the next row of the result set relative the current cursor position and positions the cursor at this row. If the cursor is positioned at the last row of the result set when this function is called the returned value will be {selected, ColNames,[]} e.i. the list of row values is empty indicating that there is no more data to fetch.

param_query(Ref, SQLQuery, Params) ->

param_query(Ref, SQLQuery, Params, TimeOut) -> ResultTuple | {error, Reason}

Types

Defines IN, OUT, and IN OUT Parameter Modes for stored procedures.

Executes a parameterized SQL query. For an example see the "Using the Erlang API" in the Erlang ODBC User's Guide.

prev(Ref) ->

prev(ConnectionReference, TimeOut) -> {selected, ColNames, Rows} | {error, Reason}

Types

Returns the previous row of the result set relative the current cursor position and positions the cursor at this row.

start() ->

start(Type) -> ok | {error, Reason}

Types

Starts the odbc application. Default type is temporary. See application(3)

stop() -> ok

Stops the odbc application. See application(3)

sql_query(Ref, SQLQuery) ->

sql_query(Ref, SQLQuery, TimeOut) -> ResultTuple | [ResultTuple] |{error, Reason}

Types

Executes a SQL query or a batch of SQL queries. If it is a SELECT query the result set is returned, on the format {selected, ColNames, Rows}. For other query types the tuple {updated, NRows} is returned, and for batched queries, if the driver supports them, this function can also return a list of result tuples.

select_count(Ref, SelectQuery) ->

select_count(Ref, SelectQuery, TimeOut) -> {ok, NrRows} | {error, Reason}

Types

SQL SELECT query.

Executes a SQL SELECT query and associates the result set with the connection. A cursor is positioned before the first row in the result set and the tuple {ok, NrRows} is returned.

select(Ref, Position, N) ->

select(Ref, Position, N, TimeOut) -> {selected, ColNames, Rows} | {error, Reason}

Types

Selection strategy, determines at which row in the result set to start the selection.

Should indicate a row number in the result set. When used together with the option relativeit will be used as an offset from the current cursor position, when used together with the option absoluteit will be interpreted as a row number.

Selects N consecutive rows of the result set. If Position is next it is semantically equivalent of calling next/[1,2] N times. If Position is {relative, Pos}, Pos will be used as an offset from the current cursor position to determine the first selected row. If Position is {absolute, Pos}, Pos will be the number of the first row selected. After this function has returned the cursor is positioned at the last selected row. If there is less then N rows left of the result set the length of Rows will be less than N. If the first row to select happens to be beyond the last row of the result set, the returned value will be {selected, ColNames,[]} e.i. the list of row values is empty indicating that there is no more data to fetch.