Commit 2db83d8a authored by terrymanu's avatar terrymanu
Browse files

refactor derived column to rewrite module

parent b4286edf

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/parsing/parser/statement/select/AbstractSelectParser.java

+0 −51
Original line number Diff line number Diff line
@@ -36,7 +36,6 @@ import com.dangdang.ddframe.rdb.sharding.parsing.parser.expr.SQLIdentifierExpr; 
import com.dangdang.ddframe.rdb.sharding.parsing.parser.expr.SQLNumberExpr;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.expr.SQLPropertyExpr;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.statement.SQLStatementParser;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.ItemsToken;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.TableToken;

import com.dangdang.ddframe.rdb.sharding.util.SQLUtil;

import com.google.common.base.Optional;
@@ -62,8 +61,6 @@ public abstract class AbstractSelectParser implements SQLStatementParser { 
    

    private int derivedColumnOffset;

    

    private ItemsToken itemsToken;

    

    public AbstractSelectParser(final SQLParser sqlParser) {

        this.sqlParser = sqlParser;

        sqlContext = new SelectSQLContext();
@@ -74,9 +71,6 @@ public abstract class AbstractSelectParser implements SQLStatementParser { 
        query();

        sqlContext.getOrderByContexts().addAll(parseOrderBy());

        customizedSelect();

        if (!itemsToken.getItems().isEmpty()) {

            sqlContext.getSqlTokens().add(itemsToken);

        }

        return sqlContext;

    }
@@ -121,23 +115,6 @@ public abstract class AbstractSelectParser implements SQLStatementParser { 
            index++;

        } while (sqlParser.skipIfEqual(Symbol.COMMA));

        sqlContext.setSelectListLastPosition(sqlParser.getLexer().getCurrentToken().getEndPosition() - sqlParser.getLexer().getCurrentToken().getLiterals().length());

        itemsToken = new ItemsToken(sqlContext.getSelectListLastPosition());

        for (SelectItemContext each : sqlContext.getItemContexts()) {

            if (each instanceof AggregationSelectItemContext) {

                AggregationSelectItemContext aggregationSelectItemContext = (AggregationSelectItemContext) each;

                if (AggregationType.AVG.equals(aggregationSelectItemContext.getAggregationType())) {

                    AggregationSelectItemContext countSelectItemContext = new AggregationSelectItemContext(

                            aggregationSelectItemContext.getInnerExpression(), Optional.of(generateDerivedColumnAlias()), -1, AggregationType.COUNT);

                    AggregationSelectItemContext sumSelectItemContext = new AggregationSelectItemContext(

                            aggregationSelectItemContext.getInnerExpression(), Optional.of(generateDerivedColumnAlias()), -1, AggregationType.SUM);

                    aggregationSelectItemContext.getDerivedAggregationSelectItemContexts().add(countSelectItemContext);

                    aggregationSelectItemContext.getDerivedAggregationSelectItemContexts().add(sumSelectItemContext);

                    // TODO 将AVG列替换成常数，避免数据库再计算无用的AVG函数

                    itemsToken.getItems().add(countSelectItemContext.getExpression() + " AS " + countSelectItemContext.getAlias().get() + " ");

                    itemsToken.getItems().add(sumSelectItemContext.getExpression() + " AS " + sumSelectItemContext.getAlias().get() + " ");

                }

            }

        }

    }

    

    private SelectItemContext parseSelectItem(final int index) {
@@ -221,20 +198,6 @@ public abstract class AbstractSelectParser implements SQLStatementParser { 
        } else {

            return Optional.absent();

        }

        if (!result.getIndex().isPresent()) {

            boolean found = false;

            String orderByExpression = result.getOwner().isPresent() ? result.getOwner().get() + "." + result.getName().get() : result.getName().get();

            for (SelectItemContext context : sqlContext.getItemContexts()) {

                if (context.getExpression().equalsIgnoreCase(orderByExpression) || orderByExpression.equalsIgnoreCase(context.getAlias().orNull())) {

                    found = true;

                    break;

                }

            }

            // TODO 需重构,目前的做法是通过补列有别名则补列,如果不包含select item则生成别名,进而补列,这里逻辑不直观

            if (!found && result.getAlias().isPresent()) {

                itemsToken.getItems().add(orderByExpression + " AS " + result.getAlias().get() + " ");

            }

        }

        return Optional.of(result);

    }
@@ -278,20 +241,6 @@ public abstract class AbstractSelectParser implements SQLStatementParser { 
            return;

        }

        sqlContext.getGroupByContexts().add(groupByContext);

    

        boolean found = false;

        String groupByExpression = groupByContext.getOwner().isPresent() ? groupByContext.getOwner().get() + "." + groupByContext.getName() : groupByContext.getName();

        for (SelectItemContext context : sqlContext.getItemContexts()) {

            if ((!context.getAlias().isPresent() && context.getExpression().equalsIgnoreCase(groupByExpression))

                    || (context.getAlias().isPresent() && context.getAlias().get().equalsIgnoreCase(groupByExpression))) {

                found = true;

                break;

            }

        }

        // TODO 需重构,目前的做法是通过补列有别名则补列,如果不包含select item则生成别名,进而补列,这里逻辑不直观

        if (!found && groupByContext.getAlias().isPresent()) {

            itemsToken.getItems().add(groupByExpression + " AS " + groupByContext.getAlias().get() + " ");

        }

    }

    

    private Optional<String> getAlias(final String name) {

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/rewrite/DerivedUtils.java

0 → 100644
+112 −0
Original line number Diff line number Diff line 
/*

 * Copyright 1999-2015 dangdang.com.

 * <p>

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 * </p>

 */



package com.dangdang.ddframe.rdb.sharding.rewrite;



import com.dangdang.ddframe.rdb.sharding.constant.AggregationType;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.AggregationSelectItemContext;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.GroupByContext;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.OrderByContext;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SelectItemContext;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SelectSQLContext;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.ItemsToken;

import com.google.common.base.Optional;



/**

 * 补列工具类.

 *

 * @author zhangliang

 */

public final class DerivedUtils {

    

    private static final String DERIVED_COUNT_ALIAS = "AVG_DERIVED_COUNT_%s";

    

    private static final String DERIVED_SUM_ALIAS = "AVG_DERIVED_SUM_%s";

    

    /**

     * 追加派生列.

     *

     * @param selectSQLContext 解析结果

     */

    public static void appendDerivedColumns(final SelectSQLContext selectSQLContext) {

        ItemsToken itemsToken = new ItemsToken(selectSQLContext.getSelectListLastPosition());

        appendAvgDerivedColumns(selectSQLContext, itemsToken);

        appendOrderByDerivedColumns(selectSQLContext, itemsToken);

        appendGroupByDerivedColumns(selectSQLContext, itemsToken);

        if (!itemsToken.getItems().isEmpty()) {

            selectSQLContext.getSqlTokens().add(itemsToken);

        }

    }

    

    private static void appendAvgDerivedColumns(final SelectSQLContext selectSQLContext, final ItemsToken itemsToken) {

        int derivedColumnOffset = 0;

        for (SelectItemContext each : selectSQLContext.getItemContexts()) {

            if (each instanceof AggregationSelectItemContext) {

                AggregationSelectItemContext aggregationSelectItemContext = (AggregationSelectItemContext) each;

                if (AggregationType.AVG.equals(aggregationSelectItemContext.getAggregationType())) {

                    AggregationSelectItemContext countSelectItemContext = new AggregationSelectItemContext(

                            aggregationSelectItemContext.getInnerExpression(), Optional.of(String.format(DERIVED_COUNT_ALIAS, derivedColumnOffset)), -1, AggregationType.COUNT);

                    AggregationSelectItemContext sumSelectItemContext = new AggregationSelectItemContext(

                            aggregationSelectItemContext.getInnerExpression(), Optional.of(String.format(DERIVED_SUM_ALIAS, derivedColumnOffset)), -1, AggregationType.SUM);

                    aggregationSelectItemContext.getDerivedAggregationSelectItemContexts().add(countSelectItemContext);

                    aggregationSelectItemContext.getDerivedAggregationSelectItemContexts().add(sumSelectItemContext);

                    // TODO 将AVG列替换成常数，避免数据库再计算无用的AVG函数

                    itemsToken.getItems().add(countSelectItemContext.getExpression() + " AS " + countSelectItemContext.getAlias().get() + " ");

                    itemsToken.getItems().add(sumSelectItemContext.getExpression() + " AS " + sumSelectItemContext.getAlias().get() + " ");

                    derivedColumnOffset++;

                }

            }

        }

    }

    

    private static void appendOrderByDerivedColumns(final SelectSQLContext selectSQLContext, final ItemsToken itemsToken) {

        for (OrderByContext each : selectSQLContext.getOrderByContexts()) {

            if (!each.getIndex().isPresent()) {

                boolean found = false;

                String orderByExpression = each.getOwner().isPresent() ? each.getOwner().get() + "." + each.getName().get() : each.getName().get();

                for (SelectItemContext context : selectSQLContext.getItemContexts()) {

                    if (context.getExpression().equalsIgnoreCase(orderByExpression) || orderByExpression.equalsIgnoreCase(context.getAlias().orNull())) {

                        found = true;

                        break;

                    }

                }

                // TODO 需重构,目前的做法是通过补列有别名则补列,如果不包含select item则生成别名,进而补列,这里逻辑不直观

                if (!found && each.getAlias().isPresent()) {

                    itemsToken.getItems().add(orderByExpression + " AS " + each.getAlias().get() + " ");

                }

            }

        }

    }

    

    private static void appendGroupByDerivedColumns(final SelectSQLContext selectSQLContext, final ItemsToken itemsToken) {

        for (GroupByContext each : selectSQLContext.getGroupByContexts()) {

            boolean found = false;

            String groupByExpression = each.getOwner().isPresent() ? each.getOwner().get() + "." + each.getName() : each.getName();

            for (SelectItemContext context : selectSQLContext.getItemContexts()) {

                if ((!context.getAlias().isPresent() && context.getExpression().equalsIgnoreCase(groupByExpression))

                        || (context.getAlias().isPresent() && context.getAlias().get().equalsIgnoreCase(groupByExpression))) {

                    found = true;

                    break;

                }

            }

            // TODO 需重构,目前的做法是通过补列有别名则补列,如果不包含select item则生成别名,进而补列,这里逻辑不直观

            if (!found && each.getAlias().isPresent()) {

                itemsToken.getItems().add(groupByExpression + " AS " + each.getAlias().get() + " ");

            }

        }

    }

}

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/rewrite/GenerateKeysUtils.java

+19 −2
Original line number Diff line number Diff line 
/*

 * Copyright 1999-2015 dangdang.com.

 * <p>

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 * </p>

 */



package com.dangdang.ddframe.rdb.sharding.rewrite;



import com.dangdang.ddframe.rdb.sharding.api.rule.ShardingRule;
@@ -12,11 +29,11 @@ import java.util.Collection; 
import java.util.List;



/**

 * .

 * 自增主键工具类.

 *

 * @author zhangliang

 */

public class GenerateKeysUtils {

public final class GenerateKeysUtils {

    

    /**

     * 追加自增主键.

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/router/SQLRouteEngine.java

+4 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.UpdateSQLContext 
import com.dangdang.ddframe.rdb.sharding.parsing.parser.exception.SQLParsingException;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.OffsetLimitToken;

import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.RowCountLimitToken;

import com.dangdang.ddframe.rdb.sharding.rewrite.DerivedUtils;

import com.dangdang.ddframe.rdb.sharding.rewrite.GenerateKeysUtils;

import com.dangdang.ddframe.rdb.sharding.rewrite.SQLBuilder;

import com.dangdang.ddframe.rdb.sharding.rewrite.SQLRewriteEngine;
@@ -98,6 +99,9 @@ public final class SQLRouteEngine { 
        if (result instanceof InsertSQLContext) {

            GenerateKeysUtils.appendGenerateKeys(shardingRule, parameters, (InsertSQLContext) result);

        }

        if (result instanceof SelectSQLContext) {

            DerivedUtils.appendDerivedColumns((SelectSQLContext) result);

        }

        return result;

    }

sharding-jdbc-core/src/test/resources/integrate/dataset/db/expect/select_aggregate/SelectAvg.xml

+1 −1
Original line number Diff line number Diff line 
<dataset>

    <t_order user_id_avg="19.5" SHARDING_GEN_1="40" SHARDING_GEN_2="780" />

    <t_order user_id_avg="19.5" AVG_DERIVED_COUNT_0="40" AVG_DERIVED_SUM_0="780" />

</dataset>