KEYCLOAK-2601 Fix incorrectly autodetected dialect with MSSQL2014

model/jpa/src/main/java/org/keycloak/connections/jpa/DefaultJpaConnectionProviderFactory.java

@@ -121,11 +121,6 @@ public class DefaultJpaConnectionProviderFactory implements JpaConnectionProvide
                         }
                     }
 
-                    String driverDialect = config.get("driverDialect");
-                    if (driverDialect != null && driverDialect.length() > 0) {
-                        properties.put("hibernate.dialect", driverDialect);
-                    }
-
                     String schema = getSchema();
                     if (schema != null) {
                         properties.put(JpaUtils.HIBERNATE_DEFAULT_SCHEMA, schema);
@@ -147,6 +142,11 @@ public class DefaultJpaConnectionProviderFactory implements JpaConnectionProvide
                     connection = getConnection();
                     try{ 
 	                    prepareOperationalInfo(connection);
+
+                        String driverDialect = detectDialect(connection);
+                        if (driverDialect != null) {
+                            properties.put("hibernate.dialect", driverDialect);
+                        }
 	                    
 	                    if (databaseSchema != null) {
 	                        logger.trace("Updating database");
@@ -209,7 +209,7 @@ public class DefaultJpaConnectionProviderFactory implements JpaConnectionProvide
             }
         }
     }
-    
+
     protected void prepareOperationalInfo(Connection connection) {
   		try {
   			operationalInfo = new LinkedHashMap<>();
@@ -225,6 +225,42 @@ public class DefaultJpaConnectionProviderFactory implements JpaConnectionProvide
   		}
   	}
 
+
+    protected String detectDialect(Connection connection) {
+        String driverDialect = config.get("driverDialect");
+        if (driverDialect != null && driverDialect.length() > 0) {
+            return driverDialect;
+        } else {
+            try {
+                String dbProductName = connection.getMetaData().getDatabaseProductName();
+                String dbProductVersion = connection.getMetaData().getDatabaseProductVersion();
+
+                // For MSSQL2014, we may need to fix the autodetected dialect by hibernate
+                if (dbProductName.equals("Microsoft SQL Server")) {
+                    String topVersionStr = dbProductVersion.split("\\.")[0];
+                    boolean shouldSet2012Dialect = true;
+                    try {
+                        int topVersion = Integer.parseInt(topVersionStr);
+                        if (topVersion < 12) {
+                            shouldSet2012Dialect = false;
+                        }
+                    } catch (NumberFormatException nfe) {
+                    }
+                    if (shouldSet2012Dialect) {
+                        String sql2012Dialect = "org.hibernate.dialect.SQLServer2012Dialect";
+                        logger.debugf("Manually override hibernate dialect to %s", sql2012Dialect);
+                        return sql2012Dialect;
+                    }
+                }
+            } catch (SQLException e) {
+                logger.warnf("Unable to detect hibernate dialect due database exception : %s", e.getMessage());
+            }
+
+            return null;
+        }
+    }
+
+
     @Override
     public Connection getConnection() {
         try {