Examples with SQLExprTableSource com.alibaba.druid.sql.ast.statement.SQLExprTableSource used on opensource projects

Example 51 with SQLExprTableSource

use of com.alibaba.druid.sql.ast.statement.SQLExprTableSource in project Mycat-Server by MyCATApache.

the class DruidMycatRouteStrategy method routeNormalSqlWithAST.

@Override
public RouteResultset routeNormalSqlWithAST(SchemaConfig schema, String stmt, RouteResultset rrs, String charset, LayerCachePool cachePool, int sqlType, ServerConnection sc) throws SQLNonTransientException {
    /**
     *  只有mysql时只支持mysql语法
     */
    SQLStatementParser parser = null;
    if (schema.isNeedSupportMultiDBType()) {
        parser = new MycatStatementParser(stmt);
    } else {
        parser = new MySqlStatementParser(stmt);
    }
    MycatSchemaStatVisitor visitor = null;
    SQLStatement statement;
    /**
     * 解析出现问题统一抛SQL语法错误
     */
    try {
        statement = parser.parseStatement();
        visitor = new MycatSchemaStatVisitor();
    } catch (Exception t) {
        LOGGER.error("DruidMycatRouteStrategyError", t);
        throw new SQLSyntaxErrorException(t);
    }
    /**
     * 检验unsupported statement
     */
    checkUnSupportedStatement(statement);
    DruidParser druidParser = DruidParserFactory.create(schema, statement, visitor);
    druidParser.parser(schema, rrs, statement, stmt, cachePool, visitor);
    DruidShardingParseInfo ctx = druidParser.getCtx();
    rrs.setTables(ctx.getTables());
    if (visitor.isSubqueryRelationOr()) {
        String err = "In subQuery,the or condition is not supported.";
        LOGGER.error(err);
        throw new SQLSyntaxErrorException(err);
    }
    /* 按照以下情况路由
			1.2.1 可以直接路由.
       		1.2.2 两个表夸库join的sql.调用calat
       		1.2.3 需要先执行subquery 的sql.把subquery拆分出来.获取结果后,与outerquery
		 */
    // add huangyiming 分片规则不一样的且表中带查询条件的则走Catlet
    List<String> tables = ctx.getTables();
    SchemaConfig schemaConf = MycatServer.getInstance().getConfig().getSchemas().get(schema.getName());
    int index = 0;
    RuleConfig firstRule = null;
    boolean directRoute = true;
    Set<String> firstDataNodes = new HashSet<String>();
    Map<String, TableConfig> tconfigs = schemaConf == null ? null : schemaConf.getTables();
    Map<String, RuleConfig> rulemap = new HashMap<>();
    if (tconfigs != null) {
        for (String tableName : tables) {
            TableConfig tc = tconfigs.get(tableName);
            if (tc == null) {
                // add 别名中取
                Map<String, String> tableAliasMap = ctx.getTableAliasMap();
                if (tableAliasMap != null && tableAliasMap.get(tableName) != null) {
                    tc = schemaConf.getTables().get(tableAliasMap.get(tableName));
                }
            }
            if (index == 0) {
                if (tc != null) {
                    firstRule = tc.getRule();
                    // 没有指定分片规则时,不做处理
                    if (firstRule == null) {
                        continue;
                    }
                    firstDataNodes.addAll(tc.getDataNodes());
                    rulemap.put(tc.getName(), firstRule);
                }
            } else {
                if (tc != null) {
                    // ER关系表的时候是可能存在字表中没有tablerule的情况,所以加上判断
                    RuleConfig ruleCfg = tc.getRule();
                    if (ruleCfg == null) {
                        // 没有指定分片规则时,不做处理
                        continue;
                    }
                    Set<String> dataNodes = new HashSet<String>();
                    dataNodes.addAll(tc.getDataNodes());
                    rulemap.put(tc.getName(), ruleCfg);
                    // 如果匹配规则不相同或者分片的datanode不相同则需要走子查询处理
                    if (firstRule != null && ((ruleCfg != null && !ruleCfg.getRuleAlgorithm().equals(firstRule.getRuleAlgorithm())) || (!dataNodes.equals(firstDataNodes)))) {
                        directRoute = false;
                        break;
                    }
                }
            }
            index++;
        }
    }
    RouteResultset rrsResult = rrs;
    if (directRoute) {
        // 直接路由
        if (!RouterUtil.isAllGlobalTable(ctx, schemaConf)) {
            if (rulemap.size() > 1 && !checkRuleField(rulemap, visitor)) {
                String err = "In case of slice table,there is no rule field in the relationship condition!";
                LOGGER.error(err);
                throw new SQLSyntaxErrorException(err);
            }
        }
        rrsResult = directRoute(rrs, ctx, schema, druidParser, statement, cachePool);
    } else {
        int subQuerySize = visitor.getSubQuerys().size();
        if (subQuerySize == 0 && ctx.getTables().size() == 2) {
            // 两表关联,考虑使用catlet
            if (!visitor.getRelationships().isEmpty()) {
                rrs.setCacheAble(false);
                rrs.setFinishedRoute(true);
                rrsResult = catletRoute(schema, ctx.getSql(), charset, sc);
            } else {
                rrsResult = directRoute(rrs, ctx, schema, druidParser, statement, cachePool);
            }
        } else if (subQuerySize == 1) {
            // 只涉及一张表的子查询,使用  MiddlerResultHandler 获取中间结果后,改写原有 sql 继续执行 TODO 后期可能会考虑多个子查询的情况.
            SQLSelect sqlselect = visitor.getSubQuerys().iterator().next();
            if (!visitor.getRelationships().isEmpty()) {
                // 当 inner query  和 outer  query  有关联条件时,暂不支持
                String err = "In case of slice table,sql have different rules,the relationship condition is not supported.";
                LOGGER.error(err);
                throw new SQLSyntaxErrorException(err);
            } else {
                SQLSelectQuery sqlSelectQuery = sqlselect.getQuery();
                if (((MySqlSelectQueryBlock) sqlSelectQuery).getFrom() instanceof SQLExprTableSource) {
                    rrs.setCacheAble(false);
                    rrs.setFinishedRoute(true);
                    rrsResult = middlerResultRoute(schema, charset, sqlselect, sqlType, statement, sc);
                }
            }
        } else if (subQuerySize >= 2) {
            String err = "In case of slice table,sql has different rules,currently only one subQuery is supported.";
            LOGGER.error(err);
            throw new SQLSyntaxErrorException(err);
        }
    }
    return rrsResult;
}