From 35b467c04f38cd27c7c263ff3d45388d92991412 Mon Sep 17 00:00:00 2001
From: Thibault Meyer <0xbaadf00d@users.noreply.github.com>
Date: Mon, 3 Jul 2017 10:45:48 +0200
Subject: [PATCH] JSON simple implementation for MSSQL (#1057)

- Use JSON_VALUE
  - Use NVARCHAR type

Signed-off-by: Thibault Meyer <meyer.thibault@gmail.com>
---
 .../sqlserver/SqlServerPlatform.java          | 16 +++++------
 .../server/core/InternalConfiguration.java    | 19 +++++++------
 .../server/core/SqlServerJsonExpression.java  | 28 +++++++++++++++++++
 3 files changed, 45 insertions(+), 18 deletions(-)
 create mode 100644 src/main/java/io/ebeaninternal/server/core/SqlServerJsonExpression.java

diff --git a/src/main/java/io/ebean/config/dbplatform/sqlserver/SqlServerPlatform.java b/src/main/java/io/ebean/config/dbplatform/sqlserver/SqlServerPlatform.java
index fdb7663c1..c874a429e 100644
--- a/src/main/java/io/ebean/config/dbplatform/sqlserver/SqlServerPlatform.java
+++ b/src/main/java/io/ebean/config/dbplatform/sqlserver/SqlServerPlatform.java
@@ -2,11 +2,7 @@ package io.ebean.config.dbplatform.sqlserver;
 
 import io.ebean.PersistBatch;
 import io.ebean.Platform;
-import io.ebean.config.dbplatform.DatabasePlatform;
-import io.ebean.config.dbplatform.DbPlatformType;
-import io.ebean.config.dbplatform.DbType;
-import io.ebean.config.dbplatform.IdType;
-import io.ebean.config.dbplatform.SqlErrorCodes;
+import io.ebean.config.dbplatform.*;
 import io.ebean.dbmigration.ddlgeneration.platform.SqlServerDdl;
 
 import java.sql.Types;
@@ -35,13 +31,13 @@ public class SqlServerPlatform extends DatabasePlatform {
     this.exceptionTranslator =
       new SqlErrorCodes()
         .addAcquireLock("1222")
-        .addDuplicateKey("2601","2627")
-        .addDataIntegrity("544","8114","8115")
+        .addDuplicateKey("2601", "2627")
+        .addDataIntegrity("544", "8114", "8115")
         .build();
 
     this.openQuote = "[";
     this.closeQuote = "]";
-    this.specialLikeCharacters =  new char[] { '%', '_', '[' };
+    this.specialLikeCharacters = new char[]{'%', '_', '['};
     this.likeClause = "like ? COLLATE Latin1_General_BIN";
 
     booleanDbType = Types.INTEGER;
@@ -63,11 +59,13 @@ public class SqlServerPlatform extends DatabasePlatform {
     dbTypeMap.put(DbType.TIME, new DbPlatformType("time"));
     dbTypeMap.put(DbType.TIMESTAMP, new DbPlatformType("datetime2"));
 
+    dbTypeMap.put(DbType.JSON, new DbPlatformType("nvarchar(max)"));
+    dbTypeMap.put(DbType.JSONB, new DbPlatformType("nvarchar(max)"));
+
   }
 
   @Override
   protected void escapeLikeCharacter(char ch, StringBuilder sb) {
     sb.append('[').append(ch).append(']');
   }
-
 }
diff --git a/src/main/java/io/ebeaninternal/server/core/InternalConfiguration.java b/src/main/java/io/ebeaninternal/server/core/InternalConfiguration.java
index 4f6c3b2f5..ab2584b5a 100644
--- a/src/main/java/io/ebeaninternal/server/core/InternalConfiguration.java
+++ b/src/main/java/io/ebeaninternal/server/core/InternalConfiguration.java
@@ -248,19 +248,20 @@ public class InternalConfiguration {
    * Return the JSON expression handler for the given database platform.
    */
   private DbExpressionHandler getDbExpressionHandler(DatabasePlatform databasePlatform) {
-
-    Platform platform = databasePlatform.getPlatform();
-    if (platform == Platform.POSTGRES) {
-      return new PostgresJsonExpression();
+    final Platform platform = databasePlatform.getPlatform();
+    switch (platform) {
+      case POSTGRES:
+        return new PostgresJsonExpression();
+      case ORACLE:
+        return new OracleDbExpression();
+      case SQLSERVER:
+        return new SqlServerJsonExpression();
+      default:
+        return new NotSupportedDbExpression();
     }
-    if (platform == Platform.ORACLE) {
-      return new OracleDbExpression();
-    }
-    return new NotSupportedDbExpression();
   }
 
   public JsonContext createJsonContext(SpiEbeanServer server) {
-
     return new DJsonContext(server, jsonFactory, typeManager);
   }
 
diff --git a/src/main/java/io/ebeaninternal/server/core/SqlServerJsonExpression.java b/src/main/java/io/ebeaninternal/server/core/SqlServerJsonExpression.java
new file mode 100644
index 000000000..a25ddea46
--- /dev/null
+++ b/src/main/java/io/ebeaninternal/server/core/SqlServerJsonExpression.java
@@ -0,0 +1,28 @@
+package io.ebeaninternal.server.core;
+
+import io.ebeaninternal.api.SpiExpressionRequest;
+import io.ebeaninternal.server.expression.Op;
+
+/**
+ * Microsoft SQL Server JSON. ARRAY expressions not supported.
+ */
+public class SqlServerJsonExpression implements DbExpressionHandler {
+
+  @Override
+  public void json(final SpiExpressionRequest request, final String propName,
+                   final String path, final Op operator, final Object value) {
+    request.append("json_value(").append(propName).append(", '$.").append(path).append("')");
+    request.append(operator.bind());
+  }
+
+  @Override
+  public void arrayContains(final SpiExpressionRequest request, final String propName,
+                            final boolean contains, final Object... values) {
+    throw new RuntimeException("ARRAY expressions not supported on Microsoft SQL Server");
+  }
+
+  @Override
+  public void arrayIsEmpty(final SpiExpressionRequest request, final String propName, final boolean empty) {
+    throw new RuntimeException("ARRAY expressions not supported on Microsoft SQL Server");
+  }
+}