From fb4f5ba617e0d77f3a598811381c5c9a300b05aa Mon Sep 17 00:00:00 2001
From: Gavin King <gavin@hibernate.org>
Date: Mon, 19 Jun 2023 22:55:17 +0200
Subject: [PATCH] HHH-16823 support for nvarchar on MySQL

In H6 we stopped producing nvarchar columns on MySQL, but it's
needed for MySQL 5.7. On the other hand, actually nvarchar is
deprecated in MySQL 8.

So use 'varchar character set utf8' instead.
---
 .../org/hibernate/dialect/MySQLDialect.java   | 26 +++++++++++++------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/MySQLDialect.java b/hibernate-core/src/main/java/org/hibernate/dialect/MySQLDialect.java
index 85f384048f..f2a30f4912 100644
--- a/hibernate-core/src/main/java/org/hibernate/dialect/MySQLDialect.java
+++ b/hibernate-core/src/main/java/org/hibernate/dialect/MySQLDialect.java
@@ -251,10 +251,18 @@ public class MySQLDialect extends Dialect {
 			case NUMERIC:
 				// it's just a synonym
 				return columnType( DECIMAL );
+
+			// on MySQL 8, the nchar/nvarchar types use a deprecated character set
+			case NCHAR:
+				return "char($l) character set utf8";
+			case NVARCHAR:
+				return "varchar($l) character set utf8";
+
 			// the maximum long LOB length is 4_294_967_295, bigger than any Java string
 			case BLOB:
 				return "longblob";
 			case NCLOB:
+				return "longtext character set utf8";
 			case CLOB:
 				return "longtext";
 
@@ -338,16 +346,18 @@ public class MySQLDialect extends Dialect {
 		}
 		ddlTypeRegistry.addDescriptor( varcharBuilder.build() );
 
+		// do not use nchar/nvarchar/ntext because these
+		// types use a deprecated character set on MySQL 8
 		final CapacityDependentDdlType.Builder nvarcharBuilder = CapacityDependentDdlType.builder(
 						NVARCHAR,
 						columnType( NCLOB ),
-						"char",
+						"char character set utf8",
 						this
 				)
-				.withTypeCapacity( getMaxVarcharLength(), "varchar($l)" )
-				.withTypeCapacity( maxMediumLobLen, "mediumtext" );
+				.withTypeCapacity( getMaxVarcharLength(), "varchar($l) character set utf8" )
+				.withTypeCapacity( maxMediumLobLen, "mediumtext character set utf8" );
 		if ( getMaxVarcharLength() < maxLobLen ) {
-			nvarcharBuilder.withTypeCapacity( maxLobLen, "text" );
+			nvarcharBuilder.withTypeCapacity( maxLobLen, "text character set utf8" );
 		}
 		ddlTypeRegistry.addDescriptor( nvarcharBuilder.build() );
 
@@ -385,10 +395,10 @@ public class MySQLDialect extends Dialect {
 		);
 
 		ddlTypeRegistry.addDescriptor(
-				CapacityDependentDdlType.builder( NCLOB, columnType( NCLOB ), "char", this )
-						.withTypeCapacity( maxTinyLobLen, "tinytext" )
-						.withTypeCapacity( maxMediumLobLen, "mediumtext" )
-						.withTypeCapacity( maxLobLen, "text" )
+				CapacityDependentDdlType.builder( NCLOB, columnType( NCLOB ), "char character set utf8", this )
+						.withTypeCapacity( maxTinyLobLen, "tinytext character set utf8" )
+						.withTypeCapacity( maxMediumLobLen, "mediumtext character set utf8" )
+						.withTypeCapacity( maxLobLen, "text character set utf8" )
 						.build()
 		);