#919 - io.ebean package initial

src/main/java/io/ebeaninternal/server/expression/ExistsQueryExpression.java

@@ -0,0 +1,146 @@
+package io.ebeaninternal.server.expression;
+
+import io.ebean.event.BeanQueryRequest;
+import io.ebeaninternal.api.HashQueryPlanBuilder;
+import io.ebeaninternal.api.ManyWhereJoins;
+import io.ebeaninternal.api.SpiEbeanServer;
+import io.ebeaninternal.api.SpiExpression;
+import io.ebeaninternal.api.SpiExpressionRequest;
+import io.ebeaninternal.api.SpiExpressionValidation;
+import io.ebeaninternal.api.SpiQuery;
+import io.ebeaninternal.server.deploy.BeanDescriptor;
+import io.ebeaninternal.server.query.CQuery;
+
+import java.io.IOException;
+import java.util.List;
+
+class ExistsQueryExpression implements SpiExpression, UnsupportedDocStoreExpression {
+
+  protected final boolean not;
+
+  protected final SpiQuery<?> subQuery;
+
+  protected List<Object> bindParams;
+
+  protected String sql;
+
+  public ExistsQueryExpression(SpiQuery<?> subQuery, boolean not) {
+    this.subQuery = subQuery;
+    this.not = not;
+  }
+
+  ExistsQueryExpression(boolean not, String sql, List<Object> bindParams) {
+    this.not = not;
+    this.sql = sql;
+    this.bindParams = bindParams;
+    this.subQuery = null;
+  }
+
+  @Override
+  public void simplify() {
+    // do nothing
+  }
+
+  @Override
+  public void writeDocQuery(DocQueryContext context) throws IOException {
+    throw new IllegalStateException("Not supported");
+  }
+
+  @Override
+  public Object getIdEqualTo(String idName) {
+    // always return null for this expression
+    return null;
+  }
+
+  @Override
+  public void prepareExpression(BeanQueryRequest<?> request) {
+
+    CQuery<?> subQuery = compileSubQuery(request);
+    this.bindParams = subQuery.getPredicates().getWhereExprBindValues();
+    this.sql = subQuery.getGeneratedSql().replace('\n', ' ');
+  }
+
+  @Override
+  public SpiExpression copyForPlanKey() {
+    return this;
+  }
+
+  /**
+   * Compile/build the sub query.
+   */
+  protected CQuery<?> compileSubQuery(BeanQueryRequest<?> queryRequest) {
+    SpiEbeanServer ebeanServer = (SpiEbeanServer) queryRequest.getEbeanServer();
+    return ebeanServer.compileQuery(subQuery, queryRequest.getTransaction());
+  }
+
+  @Override
+  public void queryPlanHash(HashQueryPlanBuilder builder) {
+    builder.add(ExistsQueryExpression.class).add(not);
+    builder.add(sql).add(bindParams.size());
+  }
+
+  @Override
+  public int queryBindHash() {
+    return subQuery.queryBindHash();
+  }
+
+  @Override
+  public void addSql(SpiExpressionRequest request) {
+
+    if (not) {
+      request.append(" not");
+    }
+    request.append(" exists (");
+    request.append(sql);
+    request.append(") ");
+  }
+
+  @Override
+  public void addBindValues(SpiExpressionRequest request) {
+
+    for (Object bindParam : bindParams) {
+      request.addBindValue(bindParam);
+    }
+  }
+
+  @Override
+  public boolean isSameByPlan(SpiExpression other) {
+    if (!(other instanceof ExistsQueryExpression)) {
+      return false;
+    }
+
+    ExistsQueryExpression that = (ExistsQueryExpression) other;
+    return this.sql.equals(that.sql)
+      && this.not == that.not
+      && this.bindParams.size() == that.bindParams.size();
+  }
+
+  @Override
+  public boolean isSameByBind(SpiExpression other) {
+    ExistsQueryExpression that = (ExistsQueryExpression) other;
+    if (this.bindParams.size() != that.bindParams.size()) {
+      return false;
+    }
+    for (int i = 0; i < bindParams.size(); i++) {
+      if (!bindParams.get(i).equals(that.bindParams.get(i))) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  @Override
+  public String nestedPath(BeanDescriptor<?> desc) {
+    return null;
+  }
+
+  @Override
+  public void containsMany(BeanDescriptor<?> desc, ManyWhereJoins whereManyJoins) {
+    // Nothing to do for exists expression
+  }
+
+  @Override
+  public void validate(SpiExpressionValidation validation) {
+    // Nothing to do for exists expression
+  }
+}