private IDbContext CreateDbContext(IDbContext ctx)
{
connection.StateChange += new StateChangeEventHandler(connection_StateChange);
if (!(connection is DbConnectionWrapper))
{
switch (DbProviderName)
{
case DbProviderNames.Oracle_ODP:
connection = new ODPConnectionWrapper(this,connection);
break;
case DbProviderNames.SQLite:
connection = new SQLiteConnectionWrapper(this, connection) { IsFileDatabase = true };
break;
case DbProviderNames.SqlCe40:
case DbProviderNames.SqlCe35:
case DbProviderNames.Oledb :
connection = new DbConnectionWrapper(this, connection) { IsFileDatabase = true };
break;
default:
connection = new DbConnectionWrapper(this,connection);
break;
}
}
ctx = new InternalDbContext(this, connection);
return ctx;
}
protected DbExpressionWriter(TextWriter writer)
: base(writer)
{
this.dbContext = ExecuteContext.DbContext;
}
public static Expression Bind(InternalDbContext dbContext, Expression exp)
{
var instance = new FunctionBinder { DbContext = dbContext };
return instance.Visit(exp);
}
/// <summary>
/// 创建DbContext（必须先注册实体到数据表的映射后才可创建DbContext）
/// </summary>
/// <returns></returns>
public IDbContext CreateDbContext()
{
Guard.NotNull(Option.Dialect, "dialect");
IDbContext ctx = null;
if (connection == null)
ctx = new InternalDbContext(this);
else
ctx = CreateDbContext(ctx);
return ctx;
}
protected DbExpressionWriter(TextWriter writer)
: base(writer)
{
this.dbContext = ExecuteContext.DbContext;
}
public static Expression Rewrite(InternalDbContext dbContext,Expression expression)
{
return new ClientJoinedProjectionRewriter(dbContext).Visit(expression);
}
private ClientJoinedProjectionRewriter(InternalDbContext dbContext)
{
this.policy = dbContext;
this.dbExpressionBuilder = dbContext.ExpressionBuilder;
}
public static Expression Rewrite(InternalDbContext dbContext, Expression expression)
{
return(new ClientJoinedProjectionRewriter(dbContext).Visit(expression));
}
private ClientJoinedProjectionRewriter(InternalDbContext dbContext)
{
this.policy = dbContext;
this.dbExpressionBuilder = dbContext.ExpressionBuilder;
}
