/// <summary>
/// 获取 String 类型的 SQL 片断
/// </summary>
/// <param name="value">值</param>
/// <param name="dbType">数据类型</param>
/// <param name="size">长度</param>
/// <returns></returns>
protected override string GetSqlValueOfString(object value, object dbType, int?size = null)
{
bool unicode = SQLiteUtils.IsUnicode(dbType);
string result = this.EscapeQuote(value.ToString(), unicode, true);
return(result);
}
/// <summary>
/// 获取 DateTimeOffset 类型的 SQL 片断
/// </summary>
/// <param name="value">值</param>
/// <param name="dbType">数据类型</param>
/// <param name="scale">小数位</param>
/// <returns></returns>
protected override string GetSqlValueOfDateTimeOffset(object value, object dbType, int?scale)
{
// 默认精度为7
string format = "yyyy-MM-dd HH:mm:ss.fffffff";
if (SQLiteUtils.IsDateTimeOffset(dbType))
{
string s = string.Empty;
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 7 ? 7 : scale.Value, 'f');
}
if (!string.IsNullOrEmpty(s))
{
format = string.Format("yyyy-MM-dd HH:mm:ss.{0}", s);
}
}
string myDateTime = ((DateTimeOffset)value).DateTime.ToString(format);
string myOffset = ((DateTimeOffset)value).Offset.ToString(@"hh\:mm");
myOffset = string.Format("{0}{1}", ((DateTimeOffset)value).Offset < TimeSpan.Zero ? '-' : '+', myOffset);
string result = string.Format("'{0} {1}'", myDateTime, myOffset);
return(result);
}
/// <summary>
/// 获取 DatetTime 类型的 SQL 片断
/// </summary>
/// <param name="value">值</param>
/// <param name="dbType">数据类型</param>
/// <param name="scale">小数位</param>
/// <returns></returns>
protected override string GetSqlValueOfDateTime(object value, object dbType, int?scale)
{
// 默认精度为3
string format = "yyyy-MM-dd HH:mm:ss.fff";
if (SQLiteUtils.IsDate(dbType))
{
format = "yyyy-MM-dd";
}
else if (SQLiteUtils.IsDateTime(dbType))
{
format = "yyyy-MM-dd HH:mm:ss.fff";
}
else if (SQLiteUtils.IsDateTime2(dbType))
{
string s = string.Empty;
format = "yyyy-MM-dd HH:mm:ss.fffffff";
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 7 ? 7 : scale.Value, 'f');
}
if (!string.IsNullOrEmpty(s))
{
format = string.Format("yyyy-MM-dd HH:mm:ss.{0}", s);
}
}
string result = this.EscapeQuote(((DateTime)value).ToString(format), false, false);
return(result);
}
/// <summary>
/// 获取 Time 类型的 SQL 片断
/// </summary>
/// <param name="value">值</param>
/// <param name="dbType">数据类型</param>
/// <param name="scale">小数位</param>
/// <returns></returns>
protected override string GetSqlValueOfTime(object value, object dbType, int?scale)
{
// SQLSERVER 的Time类型范围：00:00:00.0000000 到 23:59:59.9999999
// https://docs.microsoft.com/zh-cn/sql/t-sql/data-types/time-transact-sql?view=sql-server-2017
// 默认精度为7
string format = @"hh\:mm\:ss\.fffffff";
if (SQLiteUtils.IsTime(dbType))
{
string s = string.Empty;
if (scale != null && scale.Value > 0)
{
s = string.Empty.PadLeft(scale.Value > 7 ? 7 : scale.Value, 'f');
}
if (!string.IsNullOrEmpty(s))
{
format = string.Format(@"hh\:mm\:ss\.{0}", s);
}
}
string result = this.EscapeQuote(((TimeSpan)value).ToString(format), false, false);
return(result);
}
/// <summary>
/// 设置命令参数对象的 DbType属性
/// </summary>
/// <param name="parameter">命令参数对象</param>
/// <param name="dbType">DbType属性</param>
public static void DbType(this SQLiteParameter parameter, object dbType)
{
if (dbType != null)
{
if (dbType is DbType)
{
parameter.DbType = (DbType)dbType;
}
else
{
SQLiteUtils.ThrowException(dbType);
}
}
}
/// <summary>
/// 是否日期+时间+精度类型
/// </summary>
/// <param name="dbType">DbType属性</param>
public static bool IsDateTime2(object dbType)
{
if (dbType == null)
{
return(false);
}
else if (dbType is DbType)
{
return(((DbType)dbType) == System.Data.DbType.DateTime2);
}
else
{
return(SQLiteUtils.ThrowException(dbType));
}
}
/// <summary>
/// 访问 Contains 方法
/// </summary>
/// <param name="m">方法表达式</param>
protected override Expression VisitStringContains(MethodCallExpression m)
{
_visitor.Visit(m.Object);
if (this.NotOperands != null && this.NotOperands.Contains(m))
{
_builder.Append(" NOT");
}
_builder.Append(" LIKE ");
if (m.Arguments[0].CanEvaluate())
{
ColumnAttribute column = null;
bool isUnicode = SQLiteUtils.IsUnicode(_visitedMark.Current, out column);
string value = _constor.GetSqlValue(m.Arguments[0].Evaluate().Value, _builder.TranslateContext, column);
if (!_builder.Parameterized && value != null)
{
value = value.TrimStart('N').Trim('\'');
}
if (_builder.Parameterized)
{
_builder.Append("'%' || ");
_builder.Append(value);
_builder.Append(" || '%'");
}
else
{
if (isUnicode)
{
_builder.Append('N');
}
_builder.Append("'%");
_builder.Append(value);
_builder.Append("%'");
}
}
else
{
_builder.Append("('%' || ");
_visitor.Visit(m.Arguments[0]);
_builder.Append(" || '%')");
}
return(m);
}
/// <summary>
/// 检查字段或属性成员声明的 DbType 是否为 Unicode 数据类型
/// </summary>
/// <param name="m">将要检查的字段或属性成员</param>
/// <param name="column">字段或属性成员显示声明的列特性</param>
/// <returns></returns>
public static bool IsUnicode(MemberVisitedStack.VisitedMember m, out ColumnAttribute column)
{
column = m != null?TypeUtils.GetColumnAttribute(m.Member, m.ReflectedType) : null;
return(SQLiteUtils.IsUnicode(column == null ? null : column.DbType));
}
/// <summary>
/// 检查字段或属性成员声明的 DbType 是否为 Unicode 数据类型
/// </summary>
/// <param name="m">将要检查的字段或属性成员</param>
/// <returns></returns>
public static bool IsUnicode(MemberVisitedStack.VisitedMember m)
{
ColumnAttribute column = null;
return(SQLiteUtils.IsUnicode(m, out column));
}