opensim – Rev 1
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/*
* Copyright (c) Contributors, http://opensimulator.org/
* See CONTRIBUTORS.TXT for a full list of copyright holders.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the OpenSimulator Project nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using System.Data;
#if CSharpSqlite
using Community.CsharpSqlite.Sqlite;
#else
using Mono.Data.Sqlite;
#endif
namespace OpenSim.Data.SQLite
{
/// <summary>
/// A base class for methods needed by all SQLite database classes
/// </summary>
public class SQLiteUtil
{
/***********************************************************************
*
* Database Definition Helper Functions
*
* This should be db agnostic as we define them in ADO.NET terms
*
**********************************************************************/
/// <summary>
///
/// </summary>
/// <param name="dt"></param>
/// <param name="name"></param>
/// <param name="type"></param>
public static void createCol(DataTable dt, string name, Type type)
{
DataColumn col = new DataColumn(name, type);
dt.Columns.Add(col);
}
/***********************************************************************
*
* SQL Statement Creation Functions
*
* These functions create SQL statements for update, insert, and create.
* They can probably be factored later to have a db independant
* portion and a db specific portion
*
**********************************************************************/
/// <summary>
/// Create an insert command
/// </summary>
/// <param name="table">table name</param>
/// <param name="dt">data table</param>
/// <returns>the created command</returns>
/// <remarks>
/// This is subtle enough to deserve some commentary.
/// Instead of doing *lots* and *lots of hardcoded strings
/// for database definitions we'll use the fact that
/// realistically all insert statements look like "insert
/// into A(b, c) values(:b, :c) on the parameterized query
/// front. If we just have a list of b, c, etc... we can
/// generate these strings instead of typing them out.
/// </remarks>
public static SqliteCommand createInsertCommand(string table, DataTable dt)
{
string[] cols = new string[dt.Columns.Count];
for (int i = 0; i < dt.Columns.Count; i++)
{
DataColumn col = dt.Columns[i];
cols[i] = col.ColumnName;
}
string sql = "insert into " + table + "(";
sql += String.Join(", ", cols);
// important, the first ':' needs to be here, the rest get added in the join
sql += ") values (:";
sql += String.Join(", :", cols);
sql += ")";
SqliteCommand cmd = new SqliteCommand(sql);
// this provides the binding for all our parameters, so
// much less code than it used to be
foreach (DataColumn col in dt.Columns)
{
cmd.Parameters.Add(createSqliteParameter(col.ColumnName, col.DataType));
}
return cmd;
}
/// <summary>
/// create an update command
/// </summary>
/// <param name="table">table name</param>
/// <param name="pk"></param>
/// <param name="dt"></param>
/// <returns>the created command</returns>
public static SqliteCommand createUpdateCommand(string table, string pk, DataTable dt)
{
string sql = "update " + table + " set ";
string subsql = String.Empty;
foreach (DataColumn col in dt.Columns)
{
if (subsql.Length > 0)
{
// a map function would rock so much here
subsql += ", ";
}
subsql += col.ColumnName + "= :" + col.ColumnName;
}
sql += subsql;
sql += " where " + pk;
SqliteCommand cmd = new SqliteCommand(sql);
// this provides the binding for all our parameters, so
// much less code than it used to be
foreach (DataColumn col in dt.Columns)
{
cmd.Parameters.Add(createSqliteParameter(col.ColumnName, col.DataType));
}
return cmd;
}
/// <summary>
///
/// </summary>
/// <param name="dt">Data Table</param>
/// <returns></returns>
public static string defineTable(DataTable dt)
{
string sql = "create table " + dt.TableName + "(";
string subsql = String.Empty;
foreach (DataColumn col in dt.Columns)
{
if (subsql.Length > 0)
{
// a map function would rock so much here
subsql += ",\n";
}
subsql += col.ColumnName + " " + sqliteType(col.DataType);
if (dt.PrimaryKey.Length > 0)
{
if (col == dt.PrimaryKey[0])
{
subsql += " primary key";
}
}
}
sql += subsql;
sql += ")";
return sql;
}
/***********************************************************************
*
* Database Binding functions
*
* These will be db specific due to typing, and minor differences
* in databases.
*
**********************************************************************/
///<summary>
/// <para>
/// This is a convenience function that collapses 5 repetitive
/// lines for defining SqliteParameters to 2 parameters:
/// column name and database type.
/// </para>
///
/// <para>
/// It assumes certain conventions like :param as the param
/// name to replace in parametrized queries, and that source
/// version is always current version, both of which are fine
/// for us.
/// </para>
///</summary>
/// <param name="name"></param>
/// <param name="type"></param>
///<returns>a built sqlite parameter</returns>
public static SqliteParameter createSqliteParameter(string name, Type type)
{
SqliteParameter param = new SqliteParameter();
param.ParameterName = ":" + name;
param.DbType = dbtypeFromType(type);
param.SourceColumn = name;
param.SourceVersion = DataRowVersion.Current;
return param;
}
/***********************************************************************
*
* Type conversion functions
*
**********************************************************************/
/// <summary>
/// Type conversion function
/// </summary>
/// <param name="type">a type</param>
/// <returns>a DbType</returns>
public static DbType dbtypeFromType(Type type)
{
if (type == typeof (String))
{
return DbType.String;
}
else if (type == typeof (Int32))
{
return DbType.Int32;
}
else if (type == typeof (UInt32))
{
return DbType.UInt32;
}
else if (type == typeof (Int64))
{
return DbType.Int64;
}
else if (type == typeof (UInt64))
{
return DbType.UInt64;
}
else if (type == typeof (Double))
{
return DbType.Double;
}
else if (type == typeof (Boolean))
{
return DbType.Boolean;
}
else if (type == typeof (Byte[]))
{
return DbType.Binary;
}
else
{
return DbType.String;
}
}
/// <summary>
/// </summary>
/// <param name="type">a Type</param>
/// <returns>a string</returns>
/// <remarks>this is something we'll need to implement for each db slightly differently.</remarks>
public static string sqliteType(Type type)
{
if (type == typeof (String))
{
return "varchar(255)";
}
else if (type == typeof (Int32))
{
return "integer";
}
else if (type == typeof (UInt32))
{
return "integer";
}
else if (type == typeof (Int64))
{
return "varchar(255)";
}
else if (type == typeof (UInt64))
{
return "varchar(255)";
}
else if (type == typeof (Double))
{
return "float";
}
else if (type == typeof (Boolean))
{
return "integer";
}
else if (type == typeof (Byte[]))
{
return "blob";
}
else
{
return "string";
}
}
}
}