/// <summary>
/// 创建一个SQL参数实例。SQL参数的类型由参数的值决定。
/// </summary>
/// <param name="client"><see cref="IDbClient"/>的实例。</param>
/// <param name="name">参数的名称。</param>
/// <param name="value">参数的值。</param>
/// <returns><see cref="DbParameter"/>的实例。</returns>
public static DbParameter CreateParameter(this IDbClient client, string name, object value)
{
var p = client.CreateParameter();
p.ParameterName = name;
if (value == null)
{
p.Value = DBNull.Value;
p.DbType = DbType.AnsiString;
p.Size = 1;
}
else
{
var dbType = DbTypeConvert.LookupDbType(value.GetType());
if (dbType == DbTypeConvert.NotSupporteDbType)
{
throw new NotSupportedException(string.Format(
"The type {0} can not be converted to a DbType.", value.GetType()));
}
p.DbType = dbType;
p.Value = value;
var stringValue = value as string;
if (stringValue != null && stringValue.Length <= DbTypeConvert.DefaultStringSizeForDbParameter)
{
p.Size = DbTypeConvert.DefaultStringSizeForDbParameter;
}
}
return p;
}
public void AddDbParameterInfo(string paramName, MemberInfo memberInfo)
{
var isPropertyInfo = memberInfo is PropertyInfo;
var memberType = isPropertyInfo
? ((PropertyInfo)memberInfo).PropertyType
: ((FieldInfo)memberInfo).FieldType;
var dbType = DbTypeConvert.LookupDbType(memberType);
if (dbType == DbTypeConvert.NotSupporteDbType)
{
throw new NotSupportedException(string.Format(
"The type {0} can not be converted to a DbType.", memberType));
}
var info = new DbParameterInfo();
info.Name = paramName;
info.DbType = dbType;
info.IsString = memberType == typeof(string);
info.ValueGetter = isPropertyInfo
? PropertyAccessorGenerator.CreateGetter((PropertyInfo)memberInfo)
: FieldAccessorGenerator.CreateGetter((FieldInfo)memberInfo);
_parameterInfos.Add(info);
}
private static DbType LookupDbType(Type type)
{
var dbType = DbTypeConvert.LookupDbType(type);
if (dbType == DbTypeConvert.NotSupporteDbType)
{
throw new NotSupportedException($"The type {type} can not be converted to DbType.");
}
return(dbType);
}
private static IEnumerable <DbParameter> GenerateParameters(IDbClient client, object[] param)
{
for (int i = 0; i < param.Length; i++)
{
var value = param[i];
var p = value as DbParameter;
if (p != null)
{
yield return(p);
}
p = client.CreateParameter();
p.ParameterName = i.ToString(CultureInfo.InvariantCulture);
if (value == null)
{
p.Value = DBNull.Value;
p.DbType = DbType.AnsiString;
p.Size = 1;
}
else
{
var dbType = DbTypeConvert.LookupDbType(value.GetType());
if (dbType == DbTypeConvert.NotSupporteDbType)
{
throw new NotSupportedException(string.Format(
"The type {0} can not be converted to a DbType.", value.GetType()));
}
p.Value = value;
p.DbType = dbType;
var stringValue = value as string;
if (stringValue != null && stringValue.Length <= DbTypeConvert.DefaultStringSizeForDbParameter)
{
p.Size = DbTypeConvert.DefaultStringSizeForDbParameter;
}
}
yield return(p);
}
}