HHH-16945 Cast to varbinary for tuple distinct count on SQL Server to avoid collation issues

Author: beikov

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/SQLServerLegacyDialect.java

@@ -300,7 +300,8 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
 						"count_big",
 						"+",
 						"varchar(max)",
-						false
+						false,
+						"varbinary(max)"
 				)
 		);
 

hibernate-core/src/main/java/org/hibernate/dialect/SQLServerDialect.java

@@ -314,7 +314,8 @@ public void initializeFunctionRegistry(FunctionContributions functionContributio
 						"count_big",
 						"+",
 						"varchar(max)",
-						false
+						true,
+						"varbinary(max)"
 				)
 		);
 

hibernate-core/src/main/java/org/hibernate/dialect/function/CountFunction.java

@@ -49,6 +49,7 @@ public class CountFunction extends AbstractSqmSelfRenderingFunctionDescriptor {
 	private final String concatOperator;
 	private final String concatArgumentCastType;
 	private final boolean castDistinctStringConcat;
+	private final String distinctArgumentCastType;
 
 	public CountFunction(
 			Dialect dialect,
@@ -79,7 +80,8 @@ public CountFunction(
 				"count",
 				concatOperator,
 				concatArgumentCastType,
-				castDistinctStringConcat
+				castDistinctStringConcat,
+				concatArgumentCastType
 		);
 	}
 
@@ -91,6 +93,27 @@ public CountFunction(
 			String concatOperator,
 			String concatArgumentCastType,
 			boolean castDistinctStringConcat) {
+		this(
+				dialect,
+				typeConfiguration,
+				defaultArgumentRenderingMode,
+				countFunctionName,
+				concatOperator,
+				concatArgumentCastType,
+				castDistinctStringConcat,
+				concatArgumentCastType
+		);
+	}
+
+	public CountFunction(
+			Dialect dialect,
+			TypeConfiguration typeConfiguration,
+			SqlAstNodeRenderingMode defaultArgumentRenderingMode,
+			String countFunctionName,
+			String concatOperator,
+			String concatArgumentCastType,
+			boolean castDistinctStringConcat,
+			String distinctArgumentCastType) {
 		super(
 				"count",
 				FunctionKind.AGGREGATE,
@@ -106,6 +129,7 @@ public CountFunction(
 		this.concatOperator = concatOperator;
 		this.concatArgumentCastType = concatArgumentCastType;
 		this.castDistinctStringConcat = castDistinctStringConcat;
+		this.distinctArgumentCastType = distinctArgumentCastType;
 	}
 
 	@Override
@@ -211,7 +235,7 @@ else if ( !dialect.supportsTupleDistinctCounts() ) {
 					sqlAppender.appendSql( "')" );
 					if ( castDistinctStringConcat ) {
 						sqlAppender.appendSql( " as " );
-						sqlAppender.appendSql( concatArgumentCastType );
+						sqlAppender.appendSql( distinctArgumentCastType );
 						sqlAppender.appendSql( ')' );
 					}
 					if ( caseWrapper ) {