#900 - Error - Can't fetch JsonDB field - org.postgresql.util.PSQLException: ERROR: could not identify an equality operator for type json

src/main/java/io/ebeaninternal/api/SpiQuery.java

@@ -674,6 +674,11 @@ public interface SpiQuery<T> extends Query<T> {
    */
   boolean isDistinctQuery();
 
+  /**
+   * Return true if this was internally set to sql distinct (ie. many where predicate).
+   */
+  boolean isSqlDistinct();
+
   /**
    * Return true if this query has been specified by a user to use DISTINCT.
    */

src/main/java/io/ebeaninternal/server/query/CQueryBuilder.java

@@ -1,5 +1,6 @@
 package io.ebeaninternal.server.query;
 
+import io.ebean.Platform;
 import io.ebean.RawSql;
 import io.ebean.RawSql.ColumnMapping;
 import io.ebean.RawSql.ColumnMapping.Column;
@@ -39,8 +40,8 @@ import java.util.List;
  */
 class CQueryBuilder {
 
-  private final String tableAliasPlaceHolder;
-  private final String columnAliasPrefix;
+  protected final String tableAliasPlaceHolder;
+  protected final String columnAliasPrefix;
 
   private final SqlLimiter sqlLimiter;
 
@@ -110,7 +111,7 @@ class CQueryBuilder {
 
     predicates.prepare(true);
 
-    SqlTree sqlTree = createSqlTree(request, predicates, getHistorySupport(query), getDraftSupport(query));
+    SqlTree sqlTree = createSqlTree(request, predicates);
 
     String sql;
     if (type.equals("Delete")) {
@@ -186,7 +187,7 @@ class CQueryBuilder {
     // use RawSql or generated Sql
     predicates.prepare(true);
 
-    SqlTree sqlTree = createSqlTree(request, predicates, getHistorySupport(query), getDraftSupport(query));
+    SqlTree sqlTree = createSqlTree(request, predicates);
     SqlLimitResponse s = buildSql(null, request, predicates, sqlTree);
 
     queryPlan = new CQueryPlan(request, s.getSql(), sqlTree, false, s.isIncludesRowNumberColumn(), predicates.getLogWhereSql());
@@ -206,14 +207,14 @@ class CQueryBuilder {
   /**
    * Return the history support if this query needs it (is a 'as of' type query).
    */
-  private <T> CQueryHistorySupport getHistorySupport(SpiQuery<T> query) {
+  <T> CQueryHistorySupport getHistorySupport(SpiQuery<T> query) {
     return query.getTemporalMode() != SpiQuery.TemporalMode.CURRENT ? historySupport : null;
   }
 
   /**
    * Return the draft support (or null) for a 'asDraft' query.
    */
-  private <T> CQueryDraftSupport getDraftSupport(SpiQuery<T> query) {
+  <T> CQueryDraftSupport getDraftSupport(SpiQuery<T> query) {
     return query.getTemporalMode() == SpiQuery.TemporalMode.DRAFT ? draftSupport : null;
   }
 
@@ -248,7 +249,7 @@ class CQueryBuilder {
 
     predicates.prepare(true);
 
-    SqlTree sqlTree = createSqlTree(request, predicates, getHistorySupport(query), getDraftSupport(query));
+    SqlTree sqlTree = createSqlTree(request, predicates);
     if (SpiQuery.TemporalMode.CURRENT == query.getTemporalMode()) {
       sqlTree.addSoftDeletePredicate(query);
     }
@@ -306,7 +307,7 @@ class CQueryBuilder {
     // Build the tree structure that represents the query.
     SpiQuery<T> query = request.getQuery();
 
-    SqlTree sqlTree = createSqlTree(request, predicates, getHistorySupport(query), getDraftSupport(query));
+    SqlTree sqlTree = createSqlTree(request, predicates);
     if (query.isAsOfQuery()) {
       sqlTree.addAsOfTableAlias(query);
     } else if (SpiQuery.TemporalMode.CURRENT == query.getTemporalMode()) {
@@ -347,7 +348,7 @@ class CQueryBuilder {
    * order by clauses that are not already included for the select clause.
    * </p>
    */
-  private SqlTree createSqlTree(OrmQueryRequest<?> request, CQueryPredicates predicates, CQueryHistorySupport historySupport, CQueryDraftSupport draftSupport) {
+  private SqlTree createSqlTree(OrmQueryRequest<?> request, CQueryPredicates predicates) {
 
     if (request.isNativeSql()) {
       return createNativeSqlTree(request, predicates);
@@ -355,7 +356,7 @@ class CQueryBuilder {
     if (request.isRawSql()) {
       return createRawSqlSqlTree(request, predicates);
     }
-    return new SqlTreeBuilder(tableAliasPlaceHolder, columnAliasPrefix, request, predicates, historySupport, draftSupport).build();
+    return new SqlTreeBuilder(this, request, predicates).build();
   }
 
   /**
@@ -517,13 +518,18 @@ class CQueryBuilder {
         sb.append("select ");
         if (query.isDistinctQuery()) {
           sb.append("distinct ");
+          String distinctOn = select.getDistinctOn();
+          if (distinctOn != null) {
+            sb.append("on (");
+            sb.append(distinctOn).append(") ");
+          }
         }
       }
 
       sb.append(select.getSelectSql());
       if (query.isDistinctQuery() && dbOrderBy != null && !query.isSingleAttribute()) {
         // add the orderBy columns to the select clause (due to distinct)
-        sb.append(", ").append(convertDbOrderByForSelect(dbOrderBy));
+        sb.append(", ").append(DbOrderByTrim.trim(dbOrderBy));
       }
     }
 
@@ -639,17 +645,11 @@ class CQueryBuilder {
     return true;
   }
 
-  /**
-   * Convert the dbOrderBy clause to be safe for adding to select. This is done when 'distinct' is
-   * used.
-   */
-  private String convertDbOrderByForSelect(String dbOrderBy) {
-    // just remove the ASC and DESC keywords
-    return dbOrderBy.replaceAll("(?i)\\b asc\\b|\\b desc\\b", "");
-  }
-
   private boolean isEmpty(String s) {
     return s == null || s.isEmpty();
   }
 
+  boolean isPlatformDistinctOn() {
+    return dbPlatform.isPlatform(Platform.POSTGRES);
+  }
 }

src/main/java/io/ebeaninternal/server/query/DefaultDbSqlContext.java

@@ -54,12 +54,12 @@ class DefaultDbSqlContext implements DbSqlContext {
   /**
    * Construct for SELECT clause (with column alias settings).
    */
-  DefaultDbSqlContext(SqlTreeAlias alias, String tableAliasPlaceHolder,
-                      String columnAliasPrefix, boolean alwaysUseColumnAlias, CQueryHistorySupport historySupport, CQueryDraftSupport draftSupport) {
+  DefaultDbSqlContext(SqlTreeAlias alias, CQueryBuilder builder,
+                      boolean alwaysUseColumnAlias, CQueryHistorySupport historySupport, CQueryDraftSupport draftSupport) {
 
     this.alias = alias;
-    this.tableAliasPlaceHolder = tableAliasPlaceHolder;
-    this.columnAliasPrefix = columnAliasPrefix;
+    this.tableAliasPlaceHolder = builder.tableAliasPlaceHolder;
+    this.columnAliasPrefix = builder.columnAliasPrefix;
     this.useColumnAlias = alwaysUseColumnAlias;
     this.draftSupport = draftSupport;
     this.historySupport = historySupport;

src/main/java/io/ebeaninternal/server/query/SqlTree.java

@@ -27,6 +27,8 @@ class SqlTree {
    */
   private final String summary;
 
+  private final String distinctOn;
+
   private final String selectSql;
 
   private final String fromSql;
@@ -48,11 +50,12 @@ class SqlTree {
   /**
    * Create the SqlSelectClause.
    */
-  SqlTree(String summary, SqlTreeNode rootNode, String selectSql, String fromSql, String groupBy, String inheritanceWhereSql,
+  SqlTree(String summary, SqlTreeNode rootNode, String distinctOn, String selectSql, String fromSql, String groupBy, String inheritanceWhereSql,
           BeanProperty[] encryptedProps, BeanPropertyAssocMany<?> manyProperty, Set<String> includes, boolean includeJoins) {
 
     this.summary = summary;
     this.rootNode = rootNode;
+    this.distinctOn = distinctOn;
     this.selectSql = selectSql;
     this.fromSql = fromSql;
     this.groupBy = groupBy;
@@ -100,6 +103,10 @@ class SqlTree {
     return includes;
   }
 
+  String getDistinctOn() {
+    return distinctOn;
+  }
+
   /**
    * Return the String for the actual SQL.
    */

src/main/java/io/ebeaninternal/server/query/SqlTreeBuilder.java

@@ -46,6 +46,7 @@ public class SqlTreeBuilder {
 
   private final boolean subQuery;
 
+  private final boolean distinctOnPlatform;
   /**
    * Property if resultSet contains master and detail rows.
    */
@@ -85,6 +86,7 @@ public class SqlTreeBuilder {
     this.disableLazyLoad = request.getQuery().isDisableLazyLoading();
     this.query = null;
     this.subQuery = false;
+    this.distinctOnPlatform = false;
     this.queryDetail = queryDetail;
     this.predicates = predicates;
     this.temporalMode = SpiQuery.TemporalMode.CURRENT;
@@ -99,8 +101,7 @@ public class SqlTreeBuilder {
    * support the where and/or order by clause. If so these extra joins are added
    * to the root node.
    */
-  public SqlTreeBuilder(String tableAliasPlaceHolder, String columnAliasPrefix,
-                        OrmQueryRequest<?> request, CQueryPredicates predicates, CQueryHistorySupport historySupport, CQueryDraftSupport draftSupport) {
+  public SqlTreeBuilder(CQueryBuilder builder, OrmQueryRequest<?> request, CQueryPredicates predicates) {
 
     this.rawSql = false;
     this.rawNoId = false;
@@ -115,7 +116,11 @@ public class SqlTreeBuilder {
 
     this.predicates = predicates;
     this.alias = new SqlTreeAlias(request.getBaseTableAlias());
-    this.ctx = new DefaultDbSqlContext(alias, tableAliasPlaceHolder, columnAliasPrefix, !subQuery, historySupport, draftSupport);
+    this.distinctOnPlatform = builder.isPlatformDistinctOn();
+
+    CQueryHistorySupport historySupport = builder.getHistorySupport(query);
+    CQueryDraftSupport draftSupport = builder.getDraftSupport(query);
+    this.ctx = new DefaultDbSqlContext(alias, builder, !subQuery, historySupport, draftSupport);
   }
 
   /**
@@ -129,6 +134,7 @@ public class SqlTreeBuilder {
     buildRoot(desc);
 
     // build the actual String
+    String distinctOn = null;
     String selectSql = null;
     String fromSql = null;
     String inheritanceWhereSql = null;
@@ -139,12 +145,13 @@ public class SqlTreeBuilder {
       fromSql = buildFromClause();
       inheritanceWhereSql = buildWhereClause();
       groupBy = buildGroupByClause();
+      distinctOn = buildDistinctOn();
       encryptedProps = ctx.getEncryptedProps();
     }
 
     boolean includeJoins = alias != null && alias.isIncludeJoins();
 
-    return new SqlTree(summary.toString(), rootNode, selectSql, fromSql, groupBy, inheritanceWhereSql, encryptedProps,
+    return new SqlTree(summary.toString(), rootNode, distinctOn, selectSql, fromSql, groupBy, inheritanceWhereSql, encryptedProps,
       manyProperty, queryDetail.getFetchPaths(), includeJoins);
   }
 
@@ -164,18 +171,46 @@ public class SqlTreeBuilder {
     }
     ctx.startGroupBy();
     rootNode.appendGroupBy(ctx, subQuery);
-    String groupBy = ctx.getContent();
-    return trimComma(groupBy);
+    return trimComma(ctx.getContent());
+  }
+
+  private String buildDistinctOn() {
+
+    if (rawSql || !distinctOnPlatform || !query.isSqlDistinct() || Type.COUNT == query.getType()) {
+      return null;
+    }
+    ctx.startGroupBy();
+    rootNode.appendDistinctOn(ctx, subQuery);
+    String idCols = trimComma(ctx.getContent());
+    return idCols == null ? null : mergeOnDistinct(idCols, predicates.getDbOrderBy());
+  }
+
+  static String mergeOnDistinct(String idCols, String dbOrderBy) {
+    if (dbOrderBy == null) {
+      return idCols;
+    }
+    dbOrderBy = DbOrderByTrim.trim(dbOrderBy);
+    StringBuilder sb = new StringBuilder(dbOrderBy.length() + idCols.length() + 2);
+    sb.append(dbOrderBy);
+    String[] split = idCols.split(",");
+    for (String col : split) {
+      col = col.trim();
+      if (!dbOrderBy.contains(col)) {
+        sb.append(", ").append(col);
+      }
+    }
+    return sb.toString();
   }
 
   /**
    * Trim the first comma.
    */
   private String trimComma(String groupBy) {
-    if (groupBy.length() >= SqlTreeNode.COMMA.length()) {
-      groupBy = groupBy.substring(SqlTreeNode.COMMA.length());
+    if (groupBy.length() < SqlTreeNode.COMMA.length()) {
+      return null;
+    } else {
+      return groupBy.substring(SqlTreeNode.COMMA.length());
     }
-    return groupBy;
   }
 
   private String buildWhereClause() {

src/main/java/io/ebeaninternal/server/query/SqlTreeNode.java

@@ -25,8 +25,12 @@ interface SqlTreeNode {
   boolean isAggregation();
 
   /**
-   * Append the required column information to the SELECT part of the sql
-   * statement.
+   * Append the distinct on clause (Id properties of root and many root only).
+   */
+  void appendDistinctOn(DbSqlContext ctx, boolean subQuery);
+
+  /**
+   * Append the required column information to the select clause.
    */
   void appendSelect(DbSqlContext ctx, boolean subQuery);
 

src/main/java/io/ebeaninternal/server/query/SqlTreeNodeBean.java

@@ -33,7 +33,7 @@ class SqlTreeNodeBean implements SqlTreeNode {
 
   protected final BeanDescriptor<?> desc;
 
-  private final IdBinder idBinder;
+  protected final IdBinder idBinder;
 
   /**
    * The children which will be other SelectBean or SelectProxyBean.
@@ -57,7 +57,7 @@ class SqlTreeNodeBean implements SqlTreeNode {
   /**
    * False if report bean and has no id property.
    */
-  private final boolean readId;
+  protected final boolean readId;
 
   private final boolean disableLazyLoad;
 
@@ -171,10 +171,10 @@ class SqlTreeNodeBean implements SqlTreeNode {
       property.buildRawSqlSelectChain(prefix, selectChain);
     }
     // recursively continue reading...
-    for (SqlTreeNode aChildren : children) {
+    for (SqlTreeNode child : children) {
       // read each child... and let them set their
       // values back to this localBean
-      aChildren.buildRawSqlSelectChain(selectChain);
+      child.buildRawSqlSelectChain(selectChain);
     }
   }
 
@@ -401,6 +401,15 @@ class SqlTreeNodeBean implements SqlTreeNode {
     ctx.popJoin();
   }
 
+  /**
+   * Append the property columns to the buffer.
+   */
+  public void appendDistinctOn(DbSqlContext ctx, boolean subQuery) {
+    for (SqlTreeNode child : children) {
+      child.appendDistinctOn(ctx, subQuery);
+    }
+  }
+
   /**
    * Append the property columns to the buffer.
    */
@@ -451,8 +460,7 @@ class SqlTreeNodeBean implements SqlTreeNode {
     }
   }
 
-  private void appendSelectId(DbSqlContext ctx, BeanProperty prop) {
-
+  protected void appendSelectId(DbSqlContext ctx, BeanProperty prop) {
     if (prop != null) {
       prop.appendSelect(ctx, false);
     }

src/main/java/io/ebeaninternal/server/query/SqlTreeNodeExtraJoin.java

@@ -56,6 +56,11 @@ class SqlTreeNodeExtraJoin implements SqlTreeNode {
     // nothing to do here
   }
 
+  @Override
+  public void appendDistinctOn(DbSqlContext ctx, boolean subQuery) {
+    // do nothing here ...
+  }
+
   @Override
   public boolean isAggregation() {
     return false;

src/main/java/io/ebeaninternal/server/query/SqlTreeNodeManyRoot.java

@@ -19,6 +19,15 @@ final class SqlTreeNodeManyRoot extends SqlTreeNodeBean {
     this.manyProp = prop;
   }
 
+  /**
+   * Append the property columns to the buffer.
+   */
+  public void appendDistinctOn(DbSqlContext ctx, boolean subQuery) {
+    ctx.pushTableAlias(prefix);
+    appendSelectId(ctx, idBinder.getBeanProperty());
+    ctx.popTableAlias();
+  }
+
   @Override
   public EntityBean load(DbReadContext cquery, EntityBean parentBean, EntityBean contextParent) throws SQLException {
     // pass in null for parentBean because the localBean

src/main/java/io/ebeaninternal/server/query/SqlTreeNodeManyWhereJoin.java

@@ -60,6 +60,11 @@ class SqlTreeNodeManyWhereJoin implements SqlTreeNode {
     return false;
   }
 
+  @Override
+  public void appendDistinctOn(DbSqlContext ctx, boolean subQuery) {
+    // do nothing here ...
+  }
+
   @Override
   public void appendGroupBy(DbSqlContext ctx, boolean subQuery) {
     // do nothing here

src/main/java/io/ebeaninternal/server/query/SqlTreeNodeRoot.java

@@ -25,6 +25,18 @@ final class SqlTreeNodeRoot extends SqlTreeNodeBean {
     this.includeJoin = includeJoin;
   }
 
+  /**
+   * Append the property columns to the buffer.
+   */
+  public void appendDistinctOn(DbSqlContext ctx, boolean subQuery) {
+    if (readId) {
+      ctx.pushTableAlias(prefix);
+      appendSelectId(ctx, idBinder.getBeanProperty());
+      ctx.popTableAlias();
+      super.appendDistinctOn(ctx, subQuery);
+    }
+  }
+
   /**
    * Set AsOf support (at root level).
    */

src/main/java/io/ebeaninternal/server/querydefn/DefaultOrmQuery.java

@@ -1351,6 +1351,11 @@ public class DefaultOrmQuery<T> implements SpiQuery<T> {
     return distinct || sqlDistinct;
   }
 
+  @Override
+  public boolean isSqlDistinct() {
+    return sqlDistinct;
+  }
+
   /**
    * Internally set to use SQL DISTINCT on the query but still have id property included.
    */