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271 | ------------------------------------------------------------------------------
-- --
-- GNOGA - The GNU Omnificent GUI for Ada --
-- --
-- G N O G A . S E R V E R . D A T A B A S E --
-- --
-- S p e c --
-- --
-- --
-- Copyright (C) 2014 David Botton --
-- --
-- This library is free software; you can redistribute it and/or modify --
-- it under terms of the GNU General Public License as published by the --
-- Free Software Foundation; either version 3, or (at your option) any --
-- later version. This library is distributed in the hope that it will be --
-- useful, but WITHOUT ANY WARRANTY; without even the implied warranty of --
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are --
-- granted additional permissions described in the GCC Runtime Library --
-- Exception, version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- For more information please go to http://www.gnoga.com --
------------------------------------------------------------------------------
-- Abstract class for database access. Use one of the specific implementations
-- for MySQL, SQLLite, etc.
with Ada.Containers.Indefinite_Vectors;
with Gnoga.Types;
package Gnoga.Server.Database is
type Connection is limited interface;
type Connection_Access is access all Connection'Class;
procedure Disconnect (C : in out Connection) is abstract;
-- Disconnect from server
procedure Execute_Query
(C : in out Connection;
SQL : String) is abstract;
-- Execute an SQL Query with no result set
function Execute_Update
(C : in out Connection;
SQL : String)
return Natural is abstract;
-- Executes and SQL Query and returns the number of affected rows
function Affected_Rows
(C : Connection)
return Natural is abstract;
-- Returns the number of rows affected by an Execute_Query
function Insert_ID
(C : Connection)
return Natural is abstract;
-- Returns the last value assigned to an auto increment field upon insert
function Error_Message
(C : Connection)
return String is abstract;
-- Returns the last error message that has occurred on this connection
function List_Of_Tables
(C : Connection)
return Gnoga.Types.Data_Array_Type is abstract;
-- Return an array of table names
function List_Fields_Of_Table
(C : Connection;
Table_Name : String)
return Gnoga.Types.Data_Array_Type is abstract;
-- Return an array of field names for table
type Field_Description is record
Column_Name : String;
Data_Type : String;
Can_Be_Null : Boolean;
Default_Value : String;
end record;
package Field_Description_Arrays is new Ada.Containers.Indefinite_Vectors (Natural, Field_Description);
subtype Field_Description_Array_Type is Field_Description_Arrays.Vector;
function Field_Descriptions
(C : Connection;
Table_Name : String)
return Field_Description_Array_Type is abstract;
-- Return an array of Field_Description records describe the fields of
-- a table
function Field_Type
(Field : Field_Description)
return String;
-- Returns the field type portion of a data type, for example:
-- If the Field.Data_Type = Varchar(80) then will return Varchar
function Field_Size
(Field : Field_Description)
return Natural;
-- Returns the field size portion of a data type, for example:
-- If the Field.Data_Type = varchar(80) then will return 80
-- If the Data_Type does not have a size portion will return 0
-- If the Data_Type is a numeric with decimals, e.g. decimal(10,2)
-- then it will return the non-decimal portion.
function Field_Decimals
(Field : Field_Description)
return Natural;
-- Returns the decimal portion of a field size if it exists or 0
-- for example: if the Data_Type = float(10,2) it will return 2
function Field_Options
(Field : Field_Description)
return String;
-- Returns the field options portion of a data type, for example:
-- If the Field.Data_Type = enum('N','Y') then will return 'N','Y'
-- as this is described in the database in the same way as field
-- size, this may be used for a string representation of the size
-- as well. For example varchar(80) will return the string 80
-- This is also used for descriptions like decimal(10,2), etc.
function ID_Field_String
(C : Connection)
return String is abstract;
-- Returns the propper type format for the ID field that should be part
-- of every table used by GRAW.
-- e.g. for SQLlite = "id INTEGER PRIMARY KEY AUTOINCREMENT"
-- for MySQL = "id INTEGER PRIMARY KEY AUTO_INCREMENT"
type Recordset is interface;
type Recordset_Access is access all Recordset'Class;
function Query
(C : Connection;
SQL : String)
return Recordset'Class is abstract;
-- Execute query that returns Recordset
procedure Close (RS : in out Recordset) is abstract;
-- Close current recordset and free resources
procedure Next (RS : in out Recordset) is abstract;
-- Go to next row
function Next
(RS : in out Recordset)
return Boolean is abstract;
-- Go to next row and return true if not End of Recordset
procedure Iterate
(C : in out Connection;
SQL : in String;
Process : not null access procedure (RS : Recordset'Class)) is abstract;
-- Iterate through all rows in the result set of the query
procedure Iterate
(RS : in out Recordset;
Process : not null access procedure (RS : Recordset'Class)) is abstract;
-- Iterate through all rows in the recordset
procedure Iterate
(C : in out Connection;
SQL : String;
Process : not null access procedure (Row : Gnoga.Types.Data_Map_Type)) is abstract;
-- Iterate through all rows in the result set of the query
procedure Iterate
(RS : in out Recordset;
Process : not null access procedure (Row : Gnoga.Types.Data_Map_Type)) is abstract;
-- Iterate through all rows in the recordset
function Number_Of_Rows
(RS : Recordset)
return Natural is abstract;
-- Return number of rows in recordset
-- This function is not available in many implementations, check the
-- database specific package before considering use.
function Number_Of_Fields
(RS : Recordset)
return Natural is abstract;
-- Return number of fields in recordset
function Field_Name
(RS : Recordset;
Field_Number : Natural)
return String is abstract;
-- Return name of field
function Is_Null
(RS : Recordset;
Field_Number : Natural)
return Boolean is abstract;
function Is_Null
(RS : Recordset;
Field_Name : String)
return Boolean is abstract;
-- return True if value of field is null
function Field_Value
(RS : Recordset;
Field_Number : Natural;
Handle_Nulls : Boolean := True)
return String is abstract;
function Field_Value
(RS : Recordset;
Field_Name : String;
Handle_Nulls : Boolean := True)
return String is abstract;
-- return value of field, if Handle_Nulls is true, Null values will
-- return as empty Strings
function Field_Values
(RS : Recordset)
return Gnoga.Types.Data_Map_Type is abstract;
-- return map of all values for current row, NULL values are set to
-- an empty String
function Escape_String
(C : Connection;
S : String)
return String is abstract;
-- prepares a string for safe storage in a query
Connection_Error : exception;
-- Unable to connect to MYSQL Server or Not connected to Server
Database_Error : exception;
-- Unable to switch to specified Database
Table_Error : exception;
-- Unable to locate table or table has no fields
Query_Error : exception;
-- Unable to execute query
Empty_Recordset_Error : exception;
-- The recordset is currently empty
Empty_Row_Error : exception;
-- Attempt to read value from Row before calling Next
End_Of_Recordset : exception;
-- Attempt to go pass the last row in recordset
No_Such_Field : exception;
-- The value for a field name was requested that does not exits
Null_Field : exception;
-- The value for a Null field was requested
Not_Implemented : exception;
-- If a database method is called that is not implemented by the specific
-- database engined used this exception will be raised.
end Gnoga.Server.Database;
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