Examples with Limit com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit used on opensource projects

Example 1 with Limit

use of com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit in project Mycat-Server by MyCATApache.

the class GlobalTableUtil method convertUpdateSQL.

/**
	 * UPDATE [LOW_PRIORITY] [IGNORE] table_reference
    	SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
    	[WHERE where_condition]
    	[ORDER BY ...]
    	[LIMIT row_count]

		Multiple-table syntax:

		UPDATE [LOW_PRIORITY] [IGNORE] table_references
    	SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
    	[WHERE where_condition]
    	
    	update user, tuser set user.name='dddd',tuser.pwd='aaa' 
    	where user.id=2 and tuser.id=0;
	 * @param sql update tuser set pwd='aaa', name='digdee' where id=0;
	 * @return
	 */
public static String convertUpdateSQL(String sql) {
    try {
        MySqlStatementParser parser = new MySqlStatementParser(sql);
        SQLStatement stmt = parser.parseStatement();
        MySqlUpdateStatement update = (MySqlUpdateStatement) stmt;
        SQLTableSource ts = update.getTableSource();
        if (ts != null && ts.toString().contains(",")) {
            System.out.println(ts.toString());
            LOGGER.warn("Do not support Multiple-table udpate syntax...");
            return sql;
        }
        String tableName = StringUtil.removeBackquote(update.getTableName().getSimpleName());
        if (!isGlobalTable(tableName))
            return sql;
        if (!isInnerColExist(tableName))
            // 没有内部列
            return sql;
        StringBuilder sb = new StringBuilder(150);
        SQLExpr se = update.getWhere();
        // where中有子查询： update company set name='com' where id in (select id from xxx where ...)
        if (se instanceof SQLInSubQueryExpr) {
            // return sql;
            int idx = sql.toUpperCase().indexOf(" SET ") + 5;
            sb.append(sql.substring(0, idx)).append(GLOBAL_TABLE_MYCAT_COLUMN).append("=").append(operationTimestamp).append(",").append(sql.substring(idx));
            return sb.toString();
        }
        String where = null;
        if (update.getWhere() != null)
            where = update.getWhere().toString();
        SQLOrderBy orderBy = update.getOrderBy();
        Limit limit = update.getLimit();
        sb.append("update ").append(tableName).append(" set ");
        List<SQLUpdateSetItem> items = update.getItems();
        boolean flag = false;
        for (int i = 0; i < items.size(); i++) {
            SQLUpdateSetItem item = items.get(i);
            String col = item.getColumn().toString();
            String val = item.getValue().toString();
            if (StringUtil.removeBackquote(col).equalsIgnoreCase(GLOBAL_TABLE_MYCAT_COLUMN)) {
                flag = true;
                sb.append(col).append("=");
                if (i != items.size() - 1)
                    sb.append(operationTimestamp).append(",");
                else
                    sb.append(operationTimestamp);
            } else {
                sb.append(col).append("=");
                if (i != items.size() - 1)
                    sb.append(val).append(",");
                else
                    sb.append(val);
            }
        }
        if (!flag) {
            sb.append(",").append(GLOBAL_TABLE_MYCAT_COLUMN).append("=").append(operationTimestamp);
        }
        sb.append(" where ").append(where);
        if (orderBy != null && orderBy.getItems() != null && orderBy.getItems().size() > 0) {
            sb.append(" order by ");
            for (int i = 0; i < orderBy.getItems().size(); i++) {
                SQLSelectOrderByItem item = orderBy.getItems().get(i);
                SQLOrderingSpecification os = item.getType();
                sb.append(item.getExpr().toString());
                if (i < orderBy.getItems().size() - 1) {
                    if (os != null)
                        sb.append(" ").append(os.toString());
                    sb.append(",");
                } else {
                    if (os != null)
                        sb.append(" ").append(os.toString());
                }
            }
        }
        if (limit != null) {
            // 分为两种情况： limit 10;   limit 10,10;
            sb.append(" limit ");
            if (limit.getOffset() != null)
                sb.append(limit.getOffset().toString()).append(",");
            sb.append(limit.getRowCount().toString());
        }
        return sb.toString();
    } catch (Exception e) {
        LOGGER.warn(e.getMessage());
        return sql;
    }
}

Example 2 with Limit

use of com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit in project Mycat-Server by MyCATApache.

the class DruidSelectOracleParser method statementParse.

@Override
public void statementParse(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt) {
    SQLSelectStatement selectStmt = (SQLSelectStatement) stmt;
    SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
    //从mysql解析过来
    if (sqlSelectQuery instanceof MySqlSelectQueryBlock) {
        MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock) selectStmt.getSelect().getQuery();
        Limit limit = mysqlSelectQuery.getLimit();
        if (limit == null) {
            //使用oracle的解析，否则会有部分oracle语法识别错误
            OracleStatementParser oracleParser = new OracleStatementParser(getCtx().getSql());
            SQLSelectStatement oracleStmt = (SQLSelectStatement) oracleParser.parseStatement();
            selectStmt = oracleStmt;
            SQLSelectQuery oracleSqlSelectQuery = oracleStmt.getSelect().getQuery();
            if (oracleSqlSelectQuery instanceof OracleSelectQueryBlock) {
                parseNativePageSql(oracleStmt, rrs, (OracleSelectQueryBlock) oracleSqlSelectQuery, schema);
            }
        }
        if (isNeedParseOrderAgg) {
            parseOrderAggGroupMysql(schema, selectStmt, rrs, mysqlSelectQuery);
            //更改canRunInReadDB属性
            if ((mysqlSelectQuery.isForUpdate() || mysqlSelectQuery.isLockInShareMode()) && rrs.isAutocommit() == false) {
                rrs.setCanRunInReadDB(false);
            }
        }
    }
}

Example 3 with Limit

use of com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit in project Mycat-Server by MyCATApache.

the class DruidSelectParser method changeSql.

/**
	 * 改写sql：需要加limit的加上
	 */
@Override
public void changeSql(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt, LayerCachePool cachePool) throws SQLNonTransientException {
    tryRoute(schema, rrs, cachePool);
    rrs.copyLimitToNodes();
    SQLSelectStatement selectStmt = (SQLSelectStatement) stmt;
    SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
    if (sqlSelectQuery instanceof MySqlSelectQueryBlock) {
        MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock) selectStmt.getSelect().getQuery();
        int limitStart = 0;
        int limitSize = schema.getDefaultMaxLimit();
        //clear group having
        SQLSelectGroupByClause groupByClause = mysqlSelectQuery.getGroupBy();
        // Modified by winbill, 20160614, do NOT include having clause when routing to multiple nodes
        if (groupByClause != null && groupByClause.getHaving() != null && isRoutMultiNode(schema, rrs)) {
            groupByClause.setHaving(null);
        }
        Map<String, Map<String, Set<ColumnRoutePair>>> allConditions = getAllConditions();
        boolean isNeedAddLimit = isNeedAddLimit(schema, rrs, mysqlSelectQuery, allConditions);
        if (isNeedAddLimit) {
            Limit limit = new Limit();
            limit.setRowCount(new SQLIntegerExpr(limitSize));
            mysqlSelectQuery.setLimit(limit);
            rrs.setLimitSize(limitSize);
            String sql = getSql(rrs, stmt, isNeedAddLimit);
            rrs.changeNodeSqlAfterAddLimit(schema, getCurentDbType(), sql, 0, limitSize, true);
        }
        Limit limit = mysqlSelectQuery.getLimit();
        if (limit != null && !isNeedAddLimit) {
            SQLIntegerExpr offset = (SQLIntegerExpr) limit.getOffset();
            SQLIntegerExpr count = (SQLIntegerExpr) limit.getRowCount();
            if (offset != null) {
                limitStart = offset.getNumber().intValue();
                rrs.setLimitStart(limitStart);
            }
            if (count != null) {
                limitSize = count.getNumber().intValue();
                rrs.setLimitSize(limitSize);
            }
            if (isNeedChangeLimit(rrs)) {
                Limit changedLimit = new Limit();
                changedLimit.setRowCount(new SQLIntegerExpr(limitStart + limitSize));
                if (offset != null) {
                    if (limitStart < 0) {
                        String msg = "You have an error in your SQL syntax; check the manual that " + "corresponds to your MySQL server version for the right syntax to use near '" + limitStart + "'";
                        throw new SQLNonTransientException(ErrorCode.ER_PARSE_ERROR + " - " + msg);
                    } else {
                        changedLimit.setOffset(new SQLIntegerExpr(0));
                    }
                }
                mysqlSelectQuery.setLimit(changedLimit);
                String sql = getSql(rrs, stmt, isNeedAddLimit);
                rrs.changeNodeSqlAfterAddLimit(schema, getCurentDbType(), sql, 0, limitStart + limitSize, true);
                //设置改写后的sql
                ctx.setSql(sql);
            } else {
                rrs.changeNodeSqlAfterAddLimit(schema, getCurentDbType(), getCtx().getSql(), rrs.getLimitStart(), rrs.getLimitSize(), true);
            //	ctx.setSql(nativeSql);
            }
        }
        if (rrs.isDistTable()) {
            SQLTableSource from = mysqlSelectQuery.getFrom();
            for (RouteResultsetNode node : rrs.getNodes()) {
                SQLIdentifierExpr sqlIdentifierExpr = new SQLIdentifierExpr();
                sqlIdentifierExpr.setParent(from);
                sqlIdentifierExpr.setName(node.getSubTableName());
                SQLExprTableSource from2 = new SQLExprTableSource(sqlIdentifierExpr);
                mysqlSelectQuery.setFrom(from2);
                node.setStatement(stmt.toString());
            }
        }
        rrs.setCacheAble(isNeedCache(schema, rrs, mysqlSelectQuery, allConditions));
    }
}