Examples with Expression com.wplatform.ddal.command.expression.Expression used on opensource projects

Example 1 with Expression

use of com.wplatform.ddal.command.expression.Expression in project jdbc-shards by wplatform.

the class Replace method getPlanSQL.

@Override
public String getPlanSQL() {
    StatementBuilder buff = new StatementBuilder("REPLACE INTO ");
    buff.append(table.getSQL()).append('(');
    for (Column c : columns) {
        buff.appendExceptFirst(", ");
        buff.append(c.getSQL());
    }
    buff.append(')');
    buff.append('\n');
    if (list.size() > 0) {
        buff.append("VALUES ");
        int row = 0;
        for (Expression[] expr : list) {
            if (row++ > 0) {
                buff.append(", ");
            }
            buff.append('(');
            buff.resetCount();
            for (Expression e : expr) {
                buff.appendExceptFirst(", ");
                if (e == null) {
                    buff.append("DEFAULT");
                } else {
                    buff.append(e.getSQL());
                }
            }
            buff.append(')');
        }
    } else {
        buff.append(query.getPlanSQL());
    }
    return buff.toString();
}

Example 2 with Expression

use of com.wplatform.ddal.command.expression.Expression in project jdbc-shards by wplatform.

the class Select method getPlanSQL.

@Override
public String getPlanSQL() {
    // can not use the field sqlStatement because the parameter
    // indexes may be incorrect: ? may be in fact ?2 for a subquery
    // but indexes may be set manually as well
    Expression[] exprList = expressions.toArray(new Expression[expressions.size()]);
    StatementBuilder buff = new StatementBuilder("SELECT");
    if (distinct) {
        buff.append(" DISTINCT");
    }
    for (int i = 0; i < visibleColumnCount; i++) {
        buff.appendExceptFirst(",");
        buff.append('\n');
        buff.append(StringUtils.indent(exprList[i].getSQL(), 4, false));
    }
    buff.append("\nFROM ");
    TableFilter filter = topTableFilter;
    if (filter != null) {
        buff.resetCount();
        int i = 0;
        do {
            buff.appendExceptFirst("\n");
            buff.append(filter.getPlanSQL(i++ > 0));
            filter = filter.getJoin();
        } while (filter != null);
    } else {
        buff.resetCount();
        int i = 0;
        for (TableFilter f : topFilters) {
            do {
                buff.appendExceptFirst("\n");
                buff.append(f.getPlanSQL(i++ > 0));
                f = f.getJoin();
            } while (f != null);
        }
    }
    if (condition != null) {
        buff.append("\nWHERE ").append(StringUtils.unEnclose(condition.getSQL()));
    }
    if (groupIndex != null) {
        buff.append("\nGROUP BY ");
        buff.resetCount();
        for (int gi : groupIndex) {
            Expression g = exprList[gi];
            g = g.getNonAliasExpression();
            buff.appendExceptFirst(", ");
            buff.append(StringUtils.unEnclose(g.getSQL()));
        }
    }
    if (group != null) {
        buff.append("\nGROUP BY ");
        buff.resetCount();
        for (Expression g : group) {
            buff.appendExceptFirst(", ");
            buff.append(StringUtils.unEnclose(g.getSQL()));
        }
    }
    if (having != null) {
        // could be set in addGlobalCondition
        // in this case the query is not run directly, just getPlanSQL is
        // called
        Expression h = having;
        buff.append("\nHAVING ").append(StringUtils.unEnclose(h.getSQL()));
    } else if (havingIndex >= 0) {
        Expression h = exprList[havingIndex];
        buff.append("\nHAVING ").append(StringUtils.unEnclose(h.getSQL()));
    }
    if (sort != null) {
        buff.append("\nORDER BY ").append(sort.getSQL(exprList, visibleColumnCount));
    }
    if (orderList != null) {
        buff.append("\nORDER BY ");
        buff.resetCount();
        for (SelectOrderBy o : orderList) {
            buff.appendExceptFirst(", ");
            buff.append(StringUtils.unEnclose(o.getSQL()));
        }
    }
    if (limitExpr != null) {
        buff.append("\nLIMIT ").append(StringUtils.unEnclose(limitExpr.getSQL()));
        if (offsetExpr != null) {
            buff.append(" OFFSET ").append(StringUtils.unEnclose(offsetExpr.getSQL()));
        }
    }
    if (sampleSizeExpr != null) {
        buff.append("\nSAMPLE_SIZE ").append(StringUtils.unEnclose(sampleSizeExpr.getSQL()));
    }
    if (isForUpdate) {
        buff.append("\nFOR UPDATE");
    }
    buff.append("\n/* cost: " + cost + " */");
    return buff.toString();
}

Example 3 with Expression

use of com.wplatform.ddal.command.expression.Expression in project jdbc-shards by wplatform.

the class Select method expandColumnList.

private void expandColumnList() {
    Database db = session.getDatabase();
    // the expressions may change within the loop
    for (int i = 0; i < expressions.size(); i++) {
        Expression expr = expressions.get(i);
        if (!expr.isWildcard()) {
            continue;
        }
        String schemaName = expr.getSchemaName();
        String tableAlias = expr.getTableAlias();
        if (tableAlias == null) {
            int temp = i;
            expressions.remove(i);
            for (TableFilter filter : filters) {
                Wildcard c2 = new Wildcard(filter.getTable().getSchema().getName(), filter.getTableAlias());
                expressions.add(i++, c2);
            }
            i = temp - 1;
        } else {
            TableFilter filter = null;
            for (TableFilter f : filters) {
                if (db.equalsIdentifiers(tableAlias, f.getTableAlias())) {
                    if (schemaName == null || db.equalsIdentifiers(schemaName, f.getSchemaName())) {
                        filter = f;
                        break;
                    }
                }
            }
            if (filter == null) {
                throw DbException.get(ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1, tableAlias);
            }
            Table t = filter.getTable();
            String alias = filter.getTableAlias();
            expressions.remove(i);
            Column[] columns = t.getColumns();
            for (Column c : columns) {
                if (filter.isNaturalJoinColumn(c)) {
                    continue;
                }
                ExpressionColumn ec = new ExpressionColumn(session.getDatabase(), null, alias, c.getName());
                expressions.add(i++, ec);
            }
            i--;
        }
    }
}

Example 4 with Expression

use of com.wplatform.ddal.command.expression.Expression in project jdbc-shards by wplatform.

the class Select method isEverything.

@Override
public boolean isEverything(ExpressionVisitor visitor) {
    switch(visitor.getType()) {
        case ExpressionVisitor.DETERMINISTIC:
            {
                if (isForUpdate) {
                    return false;
                }
                for (int i = 0, size = filters.size(); i < size; i++) {
                    TableFilter f = filters.get(i);
                    if (!f.getTable().isDeterministic()) {
                        return false;
                    }
                }
                break;
            }
        case ExpressionVisitor.EVALUATABLE:
            {
                if (!session.getDatabase().getSettings().optimizeEvaluatableSubqueries) {
                    return false;
                }
                break;
            }
        case ExpressionVisitor.GET_DEPENDENCIES:
            {
                for (int i = 0, size = filters.size(); i < size; i++) {
                    TableFilter f = filters.get(i);
                    Table table = f.getTable();
                    visitor.addDependency(table);
                    table.addDependencies(visitor.getDependencies());
                }
                break;
            }
        default:
    }
    ExpressionVisitor v2 = visitor.incrementQueryLevel(1);
    boolean result = true;
    for (int i = 0, size = expressions.size(); i < size; i++) {
        Expression e = expressions.get(i);
        if (!e.isEverything(v2)) {
            result = false;
            break;
        }
    }
    if (result && condition != null && !condition.isEverything(v2)) {
        result = false;
    }
    if (result && having != null && !having.isEverything(v2)) {
        result = false;
    }
    return result;
}

Example 5 with Expression

use of com.wplatform.ddal.command.expression.Expression in project jdbc-shards by wplatform.

the class Select method prepare.

@Override
public void prepare() {
    if (isPrepared) {
        // sometimes a subquery is prepared twice (CREATE TABLE AS SELECT)
        return;
    }
    if (SysProperties.CHECK && !checkInit) {
        DbException.throwInternalError("not initialized");
    }
    if (orderList != null) {
        sort = prepareOrder(orderList, expressions.size());
        orderList = null;
    }
    for (int i = 0; i < expressions.size(); i++) {
        Expression e = expressions.get(i);
        expressions.set(i, e.optimize(session));
    }
    if (condition != null) {
        condition = condition.optimize(session);
        for (TableFilter f : filters) {
            // left outer join child on p = pc where c is null;
            if (!f.isJoinOuter() && !f.isJoinOuterIndirect()) {
                condition.createIndexConditions(session, f);
            }
        }
    }
    if (isGroupQuery && groupIndex == null && havingIndex < 0) {
        isQuickAggregateQuery = true;
    }
    cost = preparePlan();
    TableMate last = null;
    for (TableFilter filter : filters) {
        if (!filter.isFromTableMate()) {
            break;
        }
        if (filters.size() == 1) {
            isAccordantQuery = true;
            break;
        }
        TableMate table = (TableMate) filter.getTable();
        if (last != null && !last.isRelationSymmetry(table)) {
            break;
        }
        last = table;
    }
    if (distinct && session.getDatabase().getSettings().optimizeDistinct && !isGroupQuery && filters.size() == 1 && expressions.size() == 1 && condition == null) {
    //分布式的查询不合适
    }
    if (sort != null && !isGroupQuery) {
    }
    if (isGroupQuery && getGroupByExpressionCount() > 0) {
    }
    expressionArray = new Expression[expressions.size()];
    expressions.toArray(expressionArray);
    isPrepared = true;
}