Sqlserver support (#1053)

* made some tests sqlserver ready (No effective code change in src/main)

* FIX enhance packages and let all testcases inherit from BaseTestCase, so that they can be launched directly from eclipse

* ADD sqldriver in pom and datasource

* FIX: DDL-generation for sqlserver - not yet all sqlserver tests passing
mvn verify -Ddatasource.default=mssql => Tests run: 1980, Failures: 22, Errors: 44, Skipped: 16

* BaseDdlHandlerTest checks against correct sqlserver-ddl now

src/main/java/io/ebean/dbmigration/ddlgeneration/platform/BaseTableDdl.java

@@ -54,6 +54,8 @@ public class BaseTableDdl implements TableDdl {
    * Used when unique constraints specifically for OneToOne can't be created normally (MsSqlServer).
    */
   protected List<Column> externalUnique = new ArrayList<>();
+  
+  protected List<UniqueConstraint> externalCompoundUnique = new ArrayList<>();
 
   // counters used when constraint names are truncated due to maximum length
   // and these counters are used to keep the constraint name unique
@@ -85,6 +87,7 @@ public class BaseTableDdl implements TableDdl {
   protected void reset() {
     indexSet.clear();
     externalUnique.clear();
+    externalCompoundUnique.clear();
     countCheck = 0;
     countUnique = 0;
     countForeignKey = 0;
@@ -213,6 +216,18 @@ public class BaseTableDdl implements TableDdl {
         .append(platformDdl.dropIndex(uqName, tableName))
         .endOfStatement();
     }
+    
+    for (UniqueConstraint constraint : externalCompoundUnique) {
+      String uqName = constraint.getName();
+      String[] columnNames = StringHelper.delimitedToArray(constraint.getColumnNames(), ",", false);
+      write.apply()
+        .append(platformDdl.alterTableAddUniqueConstraint(tableName, uqName, columnNames))
+        .endOfStatement();
+
+      write.dropAllForeignKeys()
+        .append(platformDdl.dropIndex(uqName, tableName))
+        .endOfStatement();
+    }
   }
 
   protected void writeSequence(DdlWrite writer, CreateTable createTable, String pk) throws IOException {
@@ -406,12 +421,17 @@ public class BaseTableDdl implements TableDdl {
   protected void writeCompoundUniqueConstraints(DdlBuffer apply, CreateTable createTable) throws IOException {
 
     List<UniqueConstraint> uniqueConstraints = createTable.getUniqueConstraint();
+    boolean inlineUniqueCompound = platformDdl.isInlineUniqueOneToOne();
     for (UniqueConstraint uniqueConstraint : uniqueConstraints) {
-      String uqName = uniqueConstraint.getName();
-      String[] columns = toColumnNamesSplit(uniqueConstraint.getColumnNames());
-      apply.append(",").newLine();
-      apply.append("  constraint ").append(uqName).append(" unique");
-      appendColumns(columns, apply);
+       if (inlineUniqueCompound) {
+        String uqName = uniqueConstraint.getName();
+        String[] columns = toColumnNamesSplit(uniqueConstraint.getColumnNames());
+        apply.append(",").newLine();
+        apply.append("  constraint ").append(uqName).append(" unique");
+        appendColumns(columns, apply);
+      } else {
+        externalCompoundUnique.add(uniqueConstraint);
+      }
     }
   }
 
@@ -832,22 +852,11 @@ public class BaseTableDdl implements TableDdl {
   }
 
   protected void alterTableAddColumn(DdlBuffer buffer, String tableName, Column column, boolean onHistoryTable) throws IOException {
-
-    String convertedType = platformDdl.convert(column.getType(), false);
-    buffer.append("alter table ").append(tableName)
-      .append(" add column ").append(column.getName())
-      .append(" ").append(convertedType);
-
-    if (!onHistoryTable) {
-      if (isTrue(column.isNotnull())) {
-        buffer.append(" not null");
-      }
-      if (hasValue(column.getCheckConstraint())) {
-        buffer.append(" constraint ").append(column.getCheckConstraintName());
-        buffer.append(" ").append(column.getCheckConstraint());
-      }
+    String ddl = platformDdl.alterTableAddColumn(tableName, column, onHistoryTable);
+    if (hasValue(ddl)) {
+      buffer.append(ddl);
+      buffer.endOfStatement();
     }
-    buffer.endOfStatement();
   }
 
   protected boolean isFalse(Boolean value) {

src/main/java/io/ebean/dbmigration/ddlgeneration/platform/PlatformDdl.java

@@ -17,6 +17,7 @@ import io.ebean.dbmigration.migration.Column;
 import io.ebean.dbmigration.migration.DropHistoryTable;
 import io.ebean.dbmigration.migration.IdentityType;
 import io.ebean.dbmigration.model.MTable;
+import io.ebean.util.StringHelper;
 
 import java.io.IOException;
 import java.util.List;
@@ -74,6 +75,8 @@ public class PlatformDdl {
   protected String dropUniqueConstraint = "drop constraint";
 
   protected String addConstraint = "add constraint";
+  
+  protected String addColumn = "add column";
 
   protected String columnSetType = "";
 
@@ -375,6 +378,27 @@ public class PlatformDdl {
     appendColumns(columns, buffer);
     return buffer.toString();
   }
+  
+  public String alterTableAddColumn(String tableName, Column column, boolean onHistoryTable) throws IOException {
+
+    String convertedType = convert(column.getType(), false);
+    
+    StringBuilder buffer = new StringBuilder(90);
+    buffer.append("alter table ").append(tableName)
+      .append(' ').append(addColumn).append(' ').append(column.getName())
+      .append(' ').append(convertedType);
+
+    if (!onHistoryTable) {
+      if (isTrue(column.isNotnull())) {
+        buffer.append(" not null");
+      }
+      if (!StringHelper.isNull(column.getCheckConstraint())) {
+        buffer.append(" constraint ").append(column.getCheckConstraintName());
+        buffer.append(" ").append(column.getCheckConstraint());
+      }
+    }
+    return buffer.toString();
+  }
 
   /**
    * Return true if unique constraints for OneToOne can be inlined as normal.

src/main/java/io/ebean/dbmigration/ddlgeneration/platform/SqlServerDdl.java

@@ -15,6 +15,8 @@ public class SqlServerDdl extends PlatformDdl {
     super(platform);
     this.identitySuffix = " identity(1,1)";
     this.foreignKeyRestrict = "";
+    this.alterTableIfExists = "";
+    this.addColumn = "add";
     this.inlineUniqueOneToOne = false;
     this.columnSetDefault = "add default";
     this.dropConstraintIfExists = "drop constraint";
@@ -28,9 +30,23 @@ public class SqlServerDdl extends PlatformDdl {
 
   @Override
   public String alterTableDropForeignKey(String tableName, String fkName) {
-    return "IF OBJECT_ID('" + fkName + "', 'F') IS NOT NULL " + super.alterTableDropForeignKey(tableName, fkName);
+    int pos = tableName.lastIndexOf('.');
+    String objectId = fkName;
+    if (pos != -1) {
+      objectId = tableName.substring(0, pos + 1) + fkName;
+    } 
+    return "IF OBJECT_ID('" + objectId + "', 'F') IS NOT NULL " + super.alterTableDropForeignKey(tableName, fkName);
+  }
+  
+  @Override
+  public String dropSequence(String sequenceName) {
+    return "IF OBJECT_ID('" + sequenceName + "', 'SO') IS NOT NULL drop sequence " + sequenceName; 
   }
 
+  @Override
+  public String dropIndex(String indexName, String tableName) {
+    return "IF EXISTS (SELECT name FROM sys.indexes WHERE object_id = OBJECT_ID('" + tableName +"','U') AND name = '" + indexName + "') drop index " + indexName + " ON " + tableName;
+  }
   /**
    * MsSqlServer specific null handling on unique constraints.
    */
@@ -48,12 +64,37 @@ public class SqlServerDdl extends PlatformDdl {
       sb.append(columns[i]);
     }
     sb.append(") where");
+    String sep = " ";
     for (String column : columns) {
-      sb.append(" ").append(column).append(" is not null");
+      sb.append(sep).append(column).append(" is not null");
+      sep = " and ";
     }
     return sb.toString();
   }
 
+  /**
+   * Generate and return the create sequence DDL.
+   */
+  @Override
+  public String createSequence(String sequenceName, int initialValue, int allocationSize) {
+
+    StringBuilder sb = new StringBuilder("create sequence ");
+    sb.append(sequenceName);
+    sb.append(" as bigint ");
+    if (initialValue > 1) {
+      sb.append(" start with ").append(initialValue);
+    } else {
+      sb.append(" start with 1 ");
+    }
+    if (allocationSize > 0 && allocationSize != 50) {
+      // at this stage ignoring allocationSize 50 as this is the 'default' and
+      // not consistent with the way Ebean batch fetches sequence values
+      sb.append(" increment by ").append(allocationSize);
+    }
+    sb.append(";");
+    return sb.toString();
+  }
+  
   @Override
   public String alterColumnDefaultValue(String tableName, String columnName, String defaultValue) {
 
@@ -74,7 +115,7 @@ public class SqlServerDdl extends PlatformDdl {
     boolean notnull = (alter.isNotnull() != null) ? alter.isNotnull() : Boolean.TRUE.equals(alter.isCurrentNotnull());
     String notnullClause = notnull ? " not null" : "";
 
-    return "alter table " + tableName + " alter column " + columnName + " " + type + notnullClause;
+    return "alter table " + tableName + " " + alterColumn + " " + columnName + " " + type + notnullClause;
   }
 
   @Override

src/main/java/io/ebean/dbmigration/ddlgeneration/platform/SqlServerHistoryDdl.java

@@ -34,16 +34,25 @@ public class SqlServerHistoryDdl implements PlatformHistoryDdl {
     apply.append("alter table ").append(baseTable).newLine()
       .append("    add ").append(systemPeriodStart).append(" datetime2 GENERATED ALWAYS AS ROW START NOT NULL DEFAULT SYSUTCDATETIME(),").newLine()
       .append("        ").append(systemPeriodEnd).append("   datetime2 GENERATED ALWAYS AS ROW END   NOT NULL,").newLine()
-      .append("period for system_time (").append(systemPeriodStart).append("From, ").append(systemPeriodEnd).append("To)").endOfStatement();
+      .append("period for system_time (").append(systemPeriodStart).append(", ").append(systemPeriodEnd).append(")").endOfStatement();
 
-    apply.append("alter table ").append(baseTable).append("set (system_versioning = on)").endOfStatement();
+    String historyTable = baseTable + "_history"; // history must contain schema, otherwise you'll get
+    // Setting SYSTEM_VERSIONING to ON failed because history table 'xxx_history' is not specified in two-part name format.
+    if (historyTable.indexOf('.') == -1) {
+      historyTable = "dbo." +historyTable; // so add the default schema, if none was specified.
+    }
+    apply.append("alter table ").append(baseTable).append(" set (system_versioning = on (history_table=").append(historyTable).append("))").endOfStatement();
+    
+    DdlBuffer drop = writer.dropAll();
+    drop.append("IF OBJECT_ID('").append(baseTable).append("', 'U') IS NOT NULL alter table ").append(baseTable).append(" set (system_versioning = off)").endOfStatement();
+    drop.append("IF OBJECT_ID('").append(baseTable).append("_history', 'U') IS NOT NULL drop table ").append(baseTable).append("_history").endOfStatement();
   }
 
   @Override
   public void dropHistoryTable(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException {
     String baseTable = dropHistoryTable.getBaseTable();
     DdlBuffer apply = writer.applyHistory();
-    apply.append("alter table ").append(baseTable).append("set (system_versioning = off)").endOfStatement();
+    apply.append("alter table ").append(baseTable).append(" set (system_versioning = off)").endOfStatement();
     apply.append("alter table ").append(baseTable).append(" drop column ").append(systemPeriodStart).endOfStatement();
     apply.append("alter table ").append(baseTable).append(" drop column ").append(systemPeriodEnd).endOfStatement();
   }