#379 - Add MySql support for @History

src/main/java/com/avaje/ebean/config/dbplatform/DbHistorySupport.java

@@ -5,6 +5,14 @@ package com.avaje.ebean.config.dbplatform;
  */
 public interface DbHistorySupport {
 
+  /**
+   * Return the number of columns bound in a 'As Of' predicate.
+   * <p>
+   * Typically this is 2 but 1 for postgres using it's range type.
+   * </p>
+   */
+  int getBindCount();
+
   /**
    * Return the 'as of' predicate added for the given table alias.
    *

src/main/java/com/avaje/ebean/config/dbplatform/MySqlHistorySupport.java

@@ -0,0 +1,35 @@
+package com.avaje.ebean.config.dbplatform;
+
+/**
+ * Runtime support for @History with MySql.
+ */
+public class MySqlHistorySupport implements DbHistorySupport {
+
+  @Override
+  public int getBindCount() {
+    return 2;
+  }
+
+  @Override
+  public String getAsOfPredicate(String asOfTableAlias, String asOfSysPeriod) {
+
+    StringBuilder sb = new StringBuilder(90);
+    sb.append("(");
+    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append("_start").append(" < ? and (");
+    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append("_end").append(" is null or ");
+    sb.append(asOfTableAlias).append(".").append(asOfSysPeriod).append("_end").append(" > ?))");
+
+    // (sys_period_start < ? and (sys_period_end is null or sys_period_end > ?));
+    return sb.toString();
+  }
+
+  @Override
+  public String getSysPeriodLower(String tableAlias, String sysPeriod) {
+    return tableAlias+"."+sysPeriod+"_start";
+  }
+
+  @Override
+  public String getSysPeriodUpper(String tableAlias, String sysPeriod) {
+    return tableAlias+"."+sysPeriod+"_end";
+  }
+}

src/main/java/com/avaje/ebean/config/dbplatform/MySqlPlatform.java

@@ -26,6 +26,7 @@ public class MySqlPlatform extends DatabasePlatform {
     this.selectCountWithAlias = true;
     this.dbEncrypt = new MySqlDbEncrypt();
     this.platformDdl = new MySqlDdl(this.dbTypeMap, this.dbIdentity);
+    this.historySupport = new MySqlHistorySupport();
 
     this.dbIdentity.setIdType(IdType.IDENTITY);
     this.dbIdentity.setSupportsGetGeneratedKeys(true);
@@ -45,7 +46,6 @@ public class MySqlPlatform extends DatabasePlatform {
     dbTypeMap.put(Types.BLOB, new MySqlBlob());
     dbTypeMap.put(Types.BINARY, new DbType("binary", 255));
     dbTypeMap.put(Types.VARBINARY, new DbType("varbinary", 255));
-
   }
 
   /**

src/main/java/com/avaje/ebean/config/dbplatform/PostgresHistorySupport.java

@@ -5,6 +5,14 @@ package com.avaje.ebean.config.dbplatform;
  */
 public class PostgresHistorySupport implements DbHistorySupport {
 
+  /**
+   * Return 1 as we are using the range type and hence don't need 2 bind variables.
+   */
+  @Override
+  public int getBindCount() {
+    return 1;
+  }
+
   /**
    * Build and return the 'as of' predicate for a given table alias.
    * <p>

src/main/java/com/avaje/ebeaninternal/server/core/InternalConfiguration.java

@@ -2,6 +2,7 @@ package com.avaje.ebeaninternal.server.core;
 
 import javax.sql.DataSource;
 
+import com.avaje.ebean.config.dbplatform.DbHistorySupport;
 import com.avaje.ebeaninternal.server.deploy.generatedproperty.GeneratedPropertyFactory;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -106,7 +107,6 @@ public class InternalConfiguration {
     this.expressionFactory = new DefaultExpressionFactory(serverConfig.isExpressionEqualsWithNullAsNoop());
 
     this.typeManager = new DefaultTypeManager(serverConfig, bootupClasses);
-    this.binder = new Binder(typeManager);
 
     this.resourceManager = ResourceManagerFactory.createResourceManager(serverConfig);
     this.deployOrmXml = new DeployOrmXml(resourceManager.getResourceSource());
@@ -120,7 +120,10 @@ public class InternalConfiguration {
 
     this.transactionManager = createTransactionManager();
 
-    this.cQueryEngine = new CQueryEngine(serverConfig.getDatabasePlatform(), binder, asOfTableMapping, serverConfig.getAsOfSysPeriod());
+    DatabasePlatform databasePlatform = serverConfig.getDatabasePlatform();
+
+    this.binder = new Binder(typeManager, getAsOfBindCount(databasePlatform));
+    this.cQueryEngine = new CQueryEngine(databasePlatform, binder, asOfTableMapping, serverConfig.getAsOfSysPeriod());
 
     ExternalTransactionManager externalTransactionManager = serverConfig.getExternalTransactionManager();
     if (externalTransactionManager == null && serverConfig.isUseJtaTransactionManager()) {
@@ -135,7 +138,15 @@ public class InternalConfiguration {
     }
 
   }
-  
+
+  /**
+   * For 'As Of' queries return the number of bind variables per predicate.
+   */
+  private int getAsOfBindCount(DatabasePlatform databasePlatform) {
+    DbHistorySupport historySupport = databasePlatform.getHistorySupport();
+    return historySupport == null ? 0 : historySupport.getBindCount();
+  }
+
   /**
    * Create the TransactionManager taking into account autoCommit mode.
    */

src/main/java/com/avaje/ebeaninternal/server/persist/Binder.java

@@ -26,11 +26,21 @@ public class Binder {
 
   private final TypeManager typeManager;
 
+  private final int asOfBindCount;
+
   /**
    * Set the PreparedStatement with which to bind variables to.
    */
-  public Binder(TypeManager typeManager) {
+  public Binder(TypeManager typeManager, int asOfBindCount) {
     this.typeManager = typeManager;
+    this.asOfBindCount = asOfBindCount;
+  }
+
+  /**
+   * Return the bind count per predicate for 'As Of' query predicates.
+   */
+  public int getAsOfBindCount() {
+    return asOfBindCount;
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/query/CQueryPredicates.java

@@ -172,7 +172,7 @@ public class CQueryPredicates {
       // there is one effective date predicate per table alias
       Timestamp asOf = query.getAsOf();
       bindLog.append(" asOf ").append(asOf);
-      for (int i = 0; i < historyTableAlias.size(); i++) {
+      for (int i = 0; i < historyTableAlias.size() * binder.getAsOfBindCount(); i++) {
         binder.bindObject(dataBind, asOf);
       }
     }