- 优化 GroupBy 聚合函数 Count(bool) 解析成 sum(case when)；dotnetcore#1841

Wolffy101 · Jul 2, 2024 · 36af40a · 36af40a
1 parent a5d7595
commit 36af40a
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Showing 3 changed files with 16 additions and 111 deletions.
diff --git a/Examples/base_entity/Program.cs b/Examples/base_entity/Program.cs
@@ -619,7 +619,18 @@ static void Main(string[] args)
             BaseEntity.Initialization(fsql, () => _asyncUow.Value);
             #endregion
 
-
+
+            var sqlc001 = fsql.Select<User1>()
+                .GroupBy(a => a.GroupId)
+                .ToSql(g => new
+                {
+                    cou1 = g.Count(),
+                    cou2 = g.Count(g.Value.Nickname),
+                    cou3 = g.Count(g.Value.Nickname == "xx"),
+                    cou4 = g.Count(g.Value.Sort > 50),
+                    cou5 = g.Count(g.Value.Sort > 50 || g.Value.Username == "xx"),
+                });
+
             fsql.Select<Account>().As("aaa").Where(p => p.ID == 1).AsQueryable().Distinct().Select(p => new { p.Name, p.ID }).Count();
 
 

diff --git a/FreeSql/FreeSql.xml b/FreeSql/FreeSql.xml
diff --git a/FreeSql/Internal/CommonExpression.cs b/FreeSql/Internal/CommonExpression.cs
@@ -1194,7 +1194,10 @@ public string ExpressionLambdaToSql(Expression exp, ExpTSC tsc)
                     {
                         switch (exp3.Method.Name)
                         {
-                            case "Count": return exp3.Arguments.Count == 0 ? "count(1)" : $"count({ExpressionLambdaToSql(exp3.Arguments[0], tsc)})";
+                            case "Count":
+                                if (exp3.Arguments.Count == 0) return "count(1)";
+                                if (exp3.Arguments[0].Type == typeof(bool)) return $"sum({_common.IIF(ExpressionLambdaToSql(exp3.Arguments[0], tsc), "1", "0")})";
+                                return $"count({ExpressionLambdaToSql(exp3.Arguments[0], tsc)})";
                             case "Sum": return $"sum({ExpressionLambdaToSql(exp3.Arguments[0], tsc)})";
                             case "Avg": return $"avg({ExpressionLambdaToSql(exp3.Arguments[0], tsc)})";
                             case "Max": return $"max({ExpressionLambdaToSql(exp3.Arguments[0], tsc)})";