xuyueandClaude Opus 5.5
13c3e4c3ec
- 教材项目 8 用参数传 "2024/1/23 23:59:59"（日期和时间之间两个空格）做 BETWEEN， 比较时用 tsql_cmp 把形如日期的字符串转成标准格式；日期和时间之间允许多个空格 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
256 lines
13 KiB
C#
256 lines
13 KiB
C#
using System;
|
||
using System.Data.SqlClient;
|
||
using System.Globalization;
|
||
using Microsoft.Data.Sqlite;
|
||
|
||
namespace Sim.Data.Engine;
|
||
|
||
/// <summary>
|
||
/// 注册到 SQLite 连接上的 T-SQL 函数和运算（转写后的 SQL 调用它们，学生的 SQL 不能直接调用 tsql_ 开头的名字）。
|
||
/// 函数里抛出的 SqlException 先记在 <see cref="Pending"/>，执行语句处取出原样抛给学生（SQLite 只能传回文字信息）。
|
||
/// </summary>
|
||
internal static class Functions
|
||
{
|
||
[ThreadStatic] private static SqlException? _pending;
|
||
|
||
public static SqlException? TakePending()
|
||
{
|
||
var pending = _pending;
|
||
_pending = null;
|
||
return pending;
|
||
}
|
||
|
||
private static Exception Fail(SqlException error)
|
||
{
|
||
_pending = error;
|
||
return error;
|
||
}
|
||
|
||
public static void Register(SqliteConnection c)
|
||
{
|
||
c.CreateFunction<object?, object?, object?>("tsql_add", Add, isDeterministic: true);
|
||
c.CreateFunction<object?, object?, object?>("tsql_div", Divide, isDeterministic: true);
|
||
c.CreateFunction<object?, object?, object?>("tsql_mod", Modulo, isDeterministic: true);
|
||
c.CreateFunction("tsql_getdate", () => Values.FormatDateTime(TruncateToMilliseconds(DateTime.Now)));
|
||
c.CreateFunction<string, object?, object?>("tsql_datepart", DatePart, isDeterministic: true);
|
||
c.CreateFunction<string, object?, object?, object?>("tsql_dateadd", DateAdd, isDeterministic: true);
|
||
c.CreateFunction<string, object?, object?, object?>("tsql_datediff", DateDiff, isDeterministic: true);
|
||
c.CreateFunction<string, object?, object?, object?, object?>("tsql_convert", Convert, isDeterministic: true);
|
||
c.CreateFunction<object?, object?>("tsql_len", s => s is null ? null : (long)Text(s).TrimEnd(' ').Length, isDeterministic: true);
|
||
c.CreateFunction<object?, object?, object?>("tsql_left", (s, n) => s is null || n is null ? null : Left(Text(s), ToLong(n)), isDeterministic: true);
|
||
c.CreateFunction<object?, object?, object?>("tsql_right", (s, n) => s is null || n is null ? null : Right(Text(s), ToLong(n)), isDeterministic: true);
|
||
c.CreateFunction<object?, object?, object?>("tsql_charindex", (f, s) => f is null || s is null ? null : (long)Text(s).IndexOf(Text(f), StringComparison.OrdinalIgnoreCase) + 1, isDeterministic: true);
|
||
c.CreateFunction<object?, object?>("tsql_floor", x => x is null ? null : Math.Floor(ToDouble(x)), isDeterministic: true);
|
||
c.CreateFunction<object?, object?>("tsql_ceiling", x => x is null ? null : Math.Ceiling(ToDouble(x)), isDeterministic: true);
|
||
c.CreateFunction<object?, object?, object?>("tsql_power", (x, y) => x is null || y is null ? null : Math.Pow(ToDouble(x), ToDouble(y)), isDeterministic: true);
|
||
c.CreateFunction<object?, object?>("tsql_sqrt", x => x is null ? null : Math.Sqrt(ToDouble(x)), isDeterministic: true);
|
||
c.CreateFunction<object?, object?>("tsql_cmp", v => v is string s && Values.LooksLikeDate(s) ? Values.NormalizeDateLiteral(s) : v, isDeterministic: true);
|
||
c.CreateFunction("tsql_newid", () => Guid.NewGuid().ToString().ToUpperInvariant());
|
||
c.CreateFunction("tsql_rand", () => Random.Shared.NextDouble());
|
||
}
|
||
|
||
private static DateTime TruncateToMilliseconds(DateTime value) => new(value.Ticks - value.Ticks % TimeSpan.TicksPerMillisecond, value.Kind);
|
||
|
||
// ---------- 运算 ----------
|
||
|
||
/// <summary>T-SQL 的 +：两边都是字符串时连接，有数字时按数字相加（字符串转不成数字时报错）</summary>
|
||
private static object? Add(object? a, object? b)
|
||
{
|
||
if (a is null || b is null) return null;
|
||
if (a is string sa && b is string sb) return sa + sb;
|
||
if (a is byte[] || b is byte[]) throw Fail(SqlException.NotSupported("二进制数据的 + 运算"));
|
||
var x = Number(a);
|
||
var y = Number(b);
|
||
return x is long lx && y is long ly ? lx + ly : ToDouble(x) + ToDouble(y);
|
||
}
|
||
|
||
private static object? Divide(object? a, object? b)
|
||
{
|
||
if (a is null || b is null) return null;
|
||
var x = Number(a);
|
||
var y = Number(b);
|
||
if (ToDouble(y) == 0) throw Fail(SqlException.DivideByZero());
|
||
return x is long lx && y is long ly ? lx / ly : ToDouble(x) / ToDouble(y);
|
||
}
|
||
|
||
private static object? Modulo(object? a, object? b)
|
||
{
|
||
if (a is null || b is null) return null;
|
||
var x = Number(a);
|
||
var y = Number(b);
|
||
if (ToDouble(y) == 0) throw Fail(SqlException.DivideByZero());
|
||
return x is long lx && y is long ly ? lx % ly : ToDouble(x) % ToDouble(y);
|
||
}
|
||
|
||
/// <summary>数字原样返回；字符串按 T-SQL 隐式转换成 int（带小数点时转成 float），转不了时报 245</summary>
|
||
private static object Number(object value) => value switch
|
||
{
|
||
long or double => value,
|
||
string s when long.TryParse(s.Trim(), NumberStyles.Integer, CultureInfo.InvariantCulture, out var l) => l,
|
||
string s when s.Contains('.') && double.TryParse(s.Trim(), NumberStyles.Float, CultureInfo.InvariantCulture, out var d) => d,
|
||
_ => throw Fail(Values.ConvertError(value, "int")),
|
||
};
|
||
|
||
private static double ToDouble(object value) => value switch
|
||
{
|
||
long l => l,
|
||
double d => d,
|
||
_ => ToDouble(Number(value)),
|
||
};
|
||
|
||
private static long ToLong(object value) => value is long l ? l : (long)ToDouble(value);
|
||
|
||
private static string Text(object value) => value switch
|
||
{
|
||
string s => s,
|
||
double d => d.ToString(CultureInfo.InvariantCulture),
|
||
_ => System.Convert.ToString(value, CultureInfo.InvariantCulture) ?? "",
|
||
};
|
||
|
||
private static string Left(string s, long n) => n <= 0 ? "" : s[..(int)Math.Min(n, s.Length)];
|
||
private static string Right(string s, long n) => n <= 0 ? "" : s[^(int)Math.Min(n, s.Length)..];
|
||
|
||
// ---------- 日期 ----------
|
||
|
||
private static DateTime ToDateTime(object value)
|
||
{
|
||
if (value is string s && Values.TryParseDateTime(s, out var d)) return d;
|
||
throw Fail(SqlException.DateConvertFailed());
|
||
}
|
||
|
||
private static object? DatePart(string part, object? value)
|
||
{
|
||
if (value is null) return null;
|
||
var d = ToDateTime(value);
|
||
return part.ToLowerInvariant() switch
|
||
{
|
||
"year" or "yy" or "yyyy" => d.Year,
|
||
"quarter" or "qq" or "q" => (d.Month - 1) / 3 + 1,
|
||
"month" or "mm" or "m" => d.Month,
|
||
"dayofyear" or "dy" or "y" => d.DayOfYear,
|
||
"day" or "dd" or "d" => d.Day,
|
||
"week" or "wk" or "ww" => CultureInfo.InvariantCulture.Calendar.GetWeekOfYear(d, CalendarWeekRule.FirstDay, DayOfWeek.Sunday),
|
||
"weekday" or "dw" or "w" => (int)d.DayOfWeek + 1,
|
||
"hour" or "hh" => d.Hour,
|
||
"minute" or "mi" or "n" => d.Minute,
|
||
"second" or "ss" or "s" => d.Second,
|
||
"millisecond" or "ms" => d.Millisecond,
|
||
_ => throw Fail(new SqlException(155, $"'{part}' 不是可以识别的 datepart 选项。")),
|
||
};
|
||
}
|
||
|
||
private static object? DateAdd(string part, object? amount, object? value)
|
||
{
|
||
if (amount is null || value is null) return null;
|
||
var d = ToDateTime(value);
|
||
var n = ToLong(amount);
|
||
var result = part.ToLowerInvariant() switch
|
||
{
|
||
"year" or "yy" or "yyyy" => d.AddYears((int)n),
|
||
"quarter" or "qq" or "q" => d.AddMonths((int)n * 3),
|
||
"month" or "mm" or "m" => d.AddMonths((int)n),
|
||
"day" or "dd" or "d" or "dayofyear" or "dy" or "y" or "weekday" or "dw" or "w" => d.AddDays(n),
|
||
"week" or "wk" or "ww" => d.AddDays(n * 7),
|
||
"hour" or "hh" => d.AddHours(n),
|
||
"minute" or "mi" or "n" => d.AddMinutes(n),
|
||
"second" or "ss" or "s" => d.AddSeconds(n),
|
||
"millisecond" or "ms" => d.AddMilliseconds(n),
|
||
_ => throw Fail(new SqlException(155, $"'{part}' 不是可以识别的 dateadd 选项。")),
|
||
};
|
||
return Values.FormatDateTime(result);
|
||
}
|
||
|
||
/// <summary>和 SQL Server 一样数跨过的边界：DATEDIFF(day, '2024-01-01 23:00', '2024-01-02 01:00') = 1</summary>
|
||
private static object? DateDiff(string part, object? start, object? end)
|
||
{
|
||
if (start is null || end is null) return null;
|
||
var a = ToDateTime(start);
|
||
var b = ToDateTime(end);
|
||
return part.ToLowerInvariant() switch
|
||
{
|
||
"year" or "yy" or "yyyy" => (long)(b.Year - a.Year),
|
||
"quarter" or "qq" or "q" => (long)((b.Year - a.Year) * 4 + (b.Month - 1) / 3 - (a.Month - 1) / 3),
|
||
"month" or "mm" or "m" => (long)((b.Year - a.Year) * 12 + b.Month - a.Month),
|
||
"day" or "dd" or "d" or "dayofyear" or "dy" or "y" => (long)(b.Date - a.Date).TotalDays,
|
||
"week" or "wk" or "ww" => (long)((b.Date.AddDays(-(int)b.DayOfWeek) - a.Date.AddDays(-(int)a.DayOfWeek)).TotalDays / 7),
|
||
"hour" or "hh" => (long)(Trim(b, TimeSpan.TicksPerHour) - Trim(a, TimeSpan.TicksPerHour)).TotalHours,
|
||
"minute" or "mi" or "n" => (long)(Trim(b, TimeSpan.TicksPerMinute) - Trim(a, TimeSpan.TicksPerMinute)).TotalMinutes,
|
||
"second" or "ss" or "s" => (long)(Trim(b, TimeSpan.TicksPerSecond) - Trim(a, TimeSpan.TicksPerSecond)).TotalSeconds,
|
||
"millisecond" or "ms" => (long)(b - a).TotalMilliseconds,
|
||
_ => throw Fail(new SqlException(155, $"'{part}' 不是可以识别的 datediff 选项。")),
|
||
};
|
||
}
|
||
|
||
private static DateTime Trim(DateTime d, long unit) => new(d.Ticks - d.Ticks % unit);
|
||
|
||
// ---------- CONVERT / CAST，以及插入、修改时按列类型转换 ----------
|
||
|
||
/// <summary>tsql_convert('varchar', 10, 值, 120)：转换成 T-SQL 类型；日期按 style 格式化</summary>
|
||
private static object? Convert(string type, object? length, object? value, object? style)
|
||
{
|
||
if (value is null) return null;
|
||
var t = TSqlType.Parse(length is null ? type : $"{type}({(ToLong(length) < 0 ? "MAX" : ToLong(length).ToString(CultureInfo.InvariantCulture))})");
|
||
if (t.IsString)
|
||
{
|
||
var text = style is not null && value is string s && Values.TryParseDateTime(s, out var date)
|
||
? FormatStyle(date, (int)ToLong(style))
|
||
: Text(value);
|
||
return t.MaxLength is { } max && text.Length > max ? text[..max] : text;
|
||
}
|
||
if (t.IsInteger)
|
||
{
|
||
return value switch
|
||
{
|
||
long => value,
|
||
double d => (long)Math.Truncate(d),
|
||
string s when long.TryParse(s.Trim(), NumberStyles.Integer, CultureInfo.InvariantCulture, out var l) => l,
|
||
_ => throw Fail(Values.ConvertError(value, t.Name)),
|
||
};
|
||
}
|
||
if (t.IsBit)
|
||
{
|
||
return value switch
|
||
{
|
||
long l => l != 0 ? 1L : 0L,
|
||
double d => d != 0 ? 1L : 0L,
|
||
string s when s.Trim().Equals("true", StringComparison.OrdinalIgnoreCase) => 1L,
|
||
string s when s.Trim().Equals("false", StringComparison.OrdinalIgnoreCase) => 0L,
|
||
string s when long.TryParse(s.Trim(), out var l) => l != 0 ? 1L : 0L,
|
||
_ => throw Fail(Values.ConvertError(value, "bit")),
|
||
};
|
||
}
|
||
if (t.IsFloat)
|
||
{
|
||
return value switch
|
||
{
|
||
long l => (double)l,
|
||
double => value,
|
||
string s when double.TryParse(s.Trim(), NumberStyles.Float, CultureInfo.InvariantCulture, out var d) => d,
|
||
_ => throw Fail(Values.ConvertError(value, t.Name)),
|
||
};
|
||
}
|
||
if (t.IsDateTime || t.IsDate)
|
||
{
|
||
if (value is not string s || !Values.TryParseDateTime(s, out var d)) throw Fail(SqlException.DateConvertFailed());
|
||
return t.IsDate ? Values.FormatDate(d) : Values.FormatDateTime(d);
|
||
}
|
||
return value;
|
||
}
|
||
|
||
/// <summary>CONVERT 的日期样式（教材用 120：yyyy-mm-dd hh:mi:ss）</summary>
|
||
private static string FormatStyle(DateTime d, int style) => style switch
|
||
{
|
||
20 or 120 => d.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture),
|
||
21 or 25 or 121 => d.ToString("yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture),
|
||
23 => d.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture),
|
||
101 => d.ToString("MM/dd/yyyy", CultureInfo.InvariantCulture),
|
||
102 => d.ToString("yyyy.MM.dd", CultureInfo.InvariantCulture),
|
||
103 => d.ToString("dd/MM/yyyy", CultureInfo.InvariantCulture),
|
||
108 or 8 => d.ToString("HH:mm:ss", CultureInfo.InvariantCulture),
|
||
111 => d.ToString("yyyy/MM/dd", CultureInfo.InvariantCulture),
|
||
112 => d.ToString("yyyyMMdd", CultureInfo.InvariantCulture),
|
||
126 => d.ToString("yyyy-MM-ddTHH:mm:ss.fff", CultureInfo.InvariantCulture),
|
||
_ => d.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture),
|
||
};
|
||
}
|