Examples with UnionStatementGenerator org.datanucleus.store.rdbms.sql.UnionStatementGenerator used on opensource projects

Example 16 with UnionStatementGenerator

use of org.datanucleus.store.rdbms.sql.UnionStatementGenerator in project datanucleus-rdbms by datanucleus.

the class JoinMapStore method getSQLStatementForGet.

/**
 * Method to return an SQLStatement for retrieving the value for a key.
 * Selects the join table and optionally joins to the value table if it has its own table.
 * @param ownerOP ObjectProvider for the owning object
 * @return The SQLStatement
 */
protected SelectStatement getSQLStatementForGet(ObjectProvider ownerOP) {
    SelectStatement sqlStmt = null;
    ExecutionContext ec = ownerOP.getExecutionContext();
    final ClassLoaderResolver clr = ownerOP.getExecutionContext().getClassLoaderResolver();
    Class valueCls = clr.classForName(this.valueType);
    if (valuesAreEmbedded || valuesAreSerialised) {
        // Value is stored in join table
        sqlStmt = new SelectStatement(storeMgr, mapTable, null, null);
        sqlStmt.setClassLoaderResolver(clr);
        sqlStmt.select(sqlStmt.getPrimaryTable(), valueMapping, null);
    } else {
        // Value is stored in own table
        getMappingDef = new StatementClassMapping();
        if (!valueCmd.getFullClassName().equals(valueCls.getName())) {
            valueCls = clr.classForName(valueCmd.getFullClassName());
        }
        UnionStatementGenerator stmtGen = new UnionStatementGenerator(storeMgr, clr, valueCls, true, null, null, mapTable, null, valueMapping);
        stmtGen.setOption(SelectStatementGenerator.OPTION_SELECT_DN_TYPE);
        getMappingDef.setNucleusTypeColumnName(UnionStatementGenerator.DN_TYPE_COLUMN);
        sqlStmt = stmtGen.getStatement(ec);
        // Select the value field(s)
        SQLTable valueSqlTbl = sqlStmt.getTable(valueTable, sqlStmt.getPrimaryTable().getGroupName());
        if (valueSqlTbl == null) {
            // Root value candidate has no table, so try to find a value candidate with a table that exists in this statement
            Collection<String> valueSubclassNames = storeMgr.getSubClassesForClass(valueType, true, clr);
            if (valueSubclassNames != null && !valueSubclassNames.isEmpty()) {
                for (String valueSubclassName : valueSubclassNames) {
                    DatastoreClass valueTbl = storeMgr.getDatastoreClass(valueSubclassName, clr);
                    if (valueTbl != null) {
                        valueSqlTbl = sqlStmt.getTable(valueTbl, sqlStmt.getPrimaryTable().getGroupName());
                        if (valueSqlTbl != null) {
                            break;
                        }
                    }
                }
            }
        }
        SQLStatementHelper.selectFetchPlanOfSourceClassInStatement(sqlStmt, getMappingDef, ec.getFetchPlan(), valueSqlTbl, valueCmd, ec.getFetchPlan().getMaxFetchDepth());
    }
    // Apply condition on owner field to filter by owner
    SQLExpressionFactory exprFactory = storeMgr.getSQLExpressionFactory();
    SQLTable ownerSqlTbl = SQLStatementHelper.getSQLTableForMappingOfTable(sqlStmt, sqlStmt.getPrimaryTable(), ownerMapping);
    SQLExpression ownerExpr = exprFactory.newExpression(sqlStmt, ownerSqlTbl, ownerMapping);
    SQLExpression ownerVal = exprFactory.newLiteralParameter(sqlStmt, ownerMapping, null, "OWNER");
    sqlStmt.whereAnd(ownerExpr.eq(ownerVal), true);
    // Apply condition on key
    if (keyMapping instanceof SerialisedMapping) {
        // if the keyMapping contains a BLOB column (or any other column not supported by the database
        // as primary key), uses like instead of the operator OP_EQ (=)
        // in future do not check if the keyMapping is of ObjectMapping, but use the database
        // adapter to check the data types not supported as primary key
        // if object mapping (BLOB) use like
        SQLExpression keyExpr = exprFactory.newExpression(sqlStmt, sqlStmt.getPrimaryTable(), keyMapping);
        SQLExpression keyVal = exprFactory.newLiteralParameter(sqlStmt, keyMapping, null, "KEY");
        sqlStmt.whereAnd(new org.datanucleus.store.rdbms.sql.expression.BooleanExpression(keyExpr, Expression.OP_LIKE, keyVal), true);
    } else {
        SQLExpression keyExpr = exprFactory.newExpression(sqlStmt, sqlStmt.getPrimaryTable(), keyMapping);
        SQLExpression keyVal = exprFactory.newLiteralParameter(sqlStmt, keyMapping, null, "KEY");
        sqlStmt.whereAnd(keyExpr.eq(keyVal), true);
    }
    // Input parameter(s) - owner, key
    int inputParamNum = 1;
    StatementMappingIndex ownerIdx = new StatementMappingIndex(ownerMapping);
    StatementMappingIndex keyIdx = new StatementMappingIndex(keyMapping);
    if (sqlStmt.getNumberOfUnions() > 0) {
        // Add parameter occurrence for each union of statement
        for (int j = 0; j < sqlStmt.getNumberOfUnions() + 1; j++) {
            int[] ownerPositions = new int[ownerMapping.getNumberOfDatastoreMappings()];
            for (int k = 0; k < ownerPositions.length; k++) {
                ownerPositions[k] = inputParamNum++;
            }
            ownerIdx.addParameterOccurrence(ownerPositions);
            int[] keyPositions = new int[keyMapping.getNumberOfDatastoreMappings()];
            for (int k = 0; k < keyPositions.length; k++) {
                keyPositions[k] = inputParamNum++;
            }
            keyIdx.addParameterOccurrence(keyPositions);
        }
    } else {
        int[] ownerPositions = new int[ownerMapping.getNumberOfDatastoreMappings()];
        for (int k = 0; k < ownerPositions.length; k++) {
            ownerPositions[k] = inputParamNum++;
        }
        ownerIdx.addParameterOccurrence(ownerPositions);
        int[] keyPositions = new int[keyMapping.getNumberOfDatastoreMappings()];
        for (int k = 0; k < keyPositions.length; k++) {
            keyPositions[k] = inputParamNum++;
        }
        keyIdx.addParameterOccurrence(keyPositions);
    }
    getMappingParams = new StatementParameterMapping();
    getMappingParams.addMappingForParameter("owner", ownerIdx);
    getMappingParams.addMappingForParameter("key", keyIdx);
    return sqlStmt;
}