IDbCommand PrepareCommand(string cmdText, DbParam[] parameters, CommandType cmdType, out List <OutputParameter> outputParameters)
{
outputParameters = null;
IDbCommand cmd = this._dbConnection.CreateCommand();
cmd.CommandText = cmdText;
cmd.CommandType = cmdType;
cmd.CommandTimeout = this._commandTimeout;
if (this.IsInTransaction)
{
cmd.Transaction = this._dbTransaction;
}
if (parameters != null)
{
for (int i = 0; i < parameters.Length; i++)
{
DbParam param = parameters[i];
if (param == null)
{
continue;
}
if (param.ExplicitParameter != null)/* 如果存在创建好了的 IDbDataParameter，则直接用它。同时也忽视了 DbParam 的其他属性 */
{
cmd.Parameters.Add(param.ExplicitParameter);
continue;
}
Type parameterType;
if (param.Value == null || param.Value == DBNull.Value)
{
parameterType = param.Type ?? typeof(object);
}
else
{
parameterType = param.Value.GetType();
if (parameterType.IsEnum)
{
parameterType = Enum.GetUnderlyingType(parameterType);
}
}
IDbDataParameter parameter = null;
MappingTypeInfo mappingTypeInfo = MappingTypeSystem.GetMappingTypeInfo(parameterType);
if (mappingTypeInfo != null && mappingTypeInfo.MappingType != null)
{
parameter = mappingTypeInfo.MappingType.CreateDataParameter(cmd, param);
}
else
{
parameter = this.CreateDataParameter(cmd, param, mappingTypeInfo);
}
cmd.Parameters.Add(parameter);
OutputParameter outputParameter = null;
if (param.Direction == ParamDirection.Output || param.Direction == ParamDirection.InputOutput)
{
outputParameter = new OutputParameter(param, parameter);
if (outputParameters == null)
{
outputParameters = new List <OutputParameter>();
}
outputParameters.Add(outputParameter);
}
}
}
return(cmd);
}