Example usage for org.hibernate.hql.internal.ast HqlSqlWalker getAssignmentSpecifications

Introduction

In this page you can find the example usage for org.hibernate.hql.internal.ast HqlSqlWalker getAssignmentSpecifications.

Prototype

public ArrayList getAssignmentSpecifications() 

Source Link

Usage

From source file:com.blazebit.persistence.integration.hibernate.CustomTableBasedUpdateHandlerImpl.java

License:Apache License

public CustomTableBasedUpdateHandlerImpl(TableBasedUpdateHandlerImpl delegate, HqlSqlWalker walker) {
    this.delegate = delegate;
    // Here comes the madness...
    // We need to somehow execute our code within the temporary table scope, but since there is no way for use to do this externally,
    // we need to use invocation handlers to get a callback at the right time
    // First, we reduce the update statements
    String[] updates = delegate.getSqlStatements();
    UpdateStatement updateStatement = (UpdateStatement) walker.getAST();
    FromElement fromElement = updateStatement.getFromClause().getFromElement();
    AbstractEntityPersister targetedPersister = (AbstractEntityPersister) fromElement.getQueryable();
    String[] tableNames = targetedPersister.getConstraintOrderedTableNameClosure();
    String[][] columnNames = targetedPersister.getContraintOrderedTableKeyColumnClosure();

    int subclassCount = delegate.getTargetedQueryable().getEntityMetamodel().getSubclassEntityNames().size();
    Set<String> subclassTableNames = new HashSet<>();
    for (int i = 0; i < subclassCount; i++) {
        subclassTableNames.add(delegate.getTargetedQueryable().getSubclassTableName(i));
    }//www  . j  av  a2s  .com

    final String[] secondaryTableUpdates = updates.clone();
    final String[] secondaryTableInserts = new String[updates.length];

    StringBuilder sb = new StringBuilder();
    StringBuilder selectSb = new StringBuilder();
    String selectString = "select ";
    String inString = "IN (";
    for (int tableIndex = 0; tableIndex < tableNames.length; tableIndex++) {
        if (updates[tableIndex] != null) {
            // We introduce a dummy update statement that we react upon
            if (subclassTableNames.contains(tableNames[tableIndex])) {
                secondaryTableUpdates[tableIndex] = null;
            } else {
                sb.setLength(0);
                selectSb.setLength(0);

                boolean affected = false;
                String idSubselect = updates[tableIndex].substring(
                        updates[tableIndex].lastIndexOf(inString) + inString.length(),
                        updates[tableIndex].length() - 1);

                sb.append("insert into ").append(tableNames[tableIndex]);
                String[] keyColumnNames = columnNames[tableIndex];
                sb.append('(');

                final List<AssignmentSpecification> assignmentSpecifications = walker
                        .getAssignmentSpecifications();
                for (AssignmentSpecification assignmentSpecification : assignmentSpecifications) {
                    if (assignmentSpecification.affectsTable(tableNames[tableIndex])) {
                        String sqlAssignmentFragment = assignmentSpecification.getSqlAssignmentFragment();
                        int eqIndex = sqlAssignmentFragment.indexOf('=');
                        sb.append(sqlAssignmentFragment, 0, eqIndex);
                        sb.append(',');
                        selectSb.append(sqlAssignmentFragment, eqIndex + 1, sqlAssignmentFragment.length());
                        selectSb.append(',');

                        affected = true;
                    }
                }
                if (affected) {
                    for (int i = 0; i < keyColumnNames.length; i++) {
                        sb.append(keyColumnNames[i]);
                        sb.append(',');
                    }
                    sb.setCharAt(sb.length() - 1, ')');
                    sb.append(' ').append(selectString);
                    sb.append(selectSb);
                    sb.append(idSubselect, selectString.length(), idSubselect.length());
                    sb.append(" where not exists (select 1 from ");
                    sb.append(tableNames[tableIndex]);
                    sb.append(" a where ");

                    for (int i = 0; i < keyColumnNames.length; i++) {
                        sb.append("a.");
                        sb.append(keyColumnNames[i]);
                        sb.append(" = ");
                        sb.append(keyColumnNames[i]);
                        sb.append(" and ");
                    }

                    sb.setLength(sb.length() - " and ".length());
                    sb.append(")");

                    secondaryTableInserts[tableIndex] = sb.toString();
                }

                updates[tableIndex] = "";
            }
        }
    }

    this.secondaryTableUpdates = secondaryTableUpdates;
    this.secondaryTableInserts = secondaryTableInserts;
}

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