Java Code Examples for com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock#getFrom()

private static boolean isSupportSelect(String stmt) {
    SQLStatementParser parser = new MySqlStatementParser(stmt);
    SQLStatement statement = parser.parseStatement();
    if (!(statement instanceof SQLSelectStatement)) {
        return false;
    }

    SQLSelectQuery sqlSelectQuery = ((SQLSelectStatement) statement).getSelect().getQuery();
    if (!(sqlSelectQuery instanceof MySqlSelectQueryBlock)) {
        return false;
    }
    MySqlSelectQueryBlock selectQueryBlock = (MySqlSelectQueryBlock) sqlSelectQuery;
    SQLTableSource mysqlFrom = selectQueryBlock.getFrom();
    if (mysqlFrom != null) {
        return false;
    }
    for (SQLSelectItem item : selectQueryBlock.getSelectList()) {
        SQLExpr selectItem = item.getExpr();
        if (!isVariantRef(selectItem)) {
            return false;
        }
    }
    return true;
}
 

/**
 * get table name of field in between expr
 *
 */
private String getOwnerTableName(SQLBetweenExpr betweenExpr, String column) {
    if (aliasMap.size() == 1) { //only has 1 table
        return aliasMap.keySet().iterator().next();
    } else if (aliasMap.size() == 0) { //no table
        return "";
    } else { // multi tables
        for (Column col : columns.values()) {
            if (col.getName().equals(column)) {
                return col.getTable();
            }
        }

        //parser from parent
        SQLObject parent = betweenExpr.getParent();
        if (parent instanceof SQLBinaryOpExpr) {
            parent = parent.getParent();
        }

        if (parent instanceof MySqlSelectQueryBlock) {
            MySqlSelectQueryBlock select = (MySqlSelectQueryBlock) parent;
            if (select.getFrom() instanceof SQLJoinTableSource) {
                SQLJoinTableSource joinTableSource = (SQLJoinTableSource) select.getFrom();
                //FIXME :left as driven table
                return joinTableSource.getLeft().toString();
            } else if (select.getFrom() instanceof SQLExprTableSource) {
                return select.getFrom().toString();
            }
        } else if (parent instanceof SQLUpdateStatement) {
            SQLUpdateStatement update = (SQLUpdateStatement) parent;
            return update.getTableName().getSimpleName();
        } else if (parent instanceof SQLDeleteStatement) {
            SQLDeleteStatement delete = (SQLDeleteStatement) parent;
            return delete.getTableName().getSimpleName();
        }
    }
    return "";
}
 

@Test
public void testJoinCondition() {
    MySqlSelectQueryBlock query = getQuery("select a.col1,b.col2  from table1 a inner join table2 b on a.id =b.id");
    SQLJoinTableSource from = (SQLJoinTableSource) query.getFrom();

    MySQLItemVisitor v = new MySQLItemVisitor(this.currentDb, utf8Charset,null, null);
    from.getCondition().accept(v);
    Item item = v.getItem();
    Assert.assertEquals(true, "a.id = b.id".equals(item.getItemName()));
}
 

public boolean visit(MySqlSelectQueryBlock x) {
	if (x.getOrderBy() != null) {
		x.getOrderBy().setParent(x);
	}

	boolean rewriteDistinct = false;
	if (x.getSelectList() != null) {
		rewriteDistinct = visitSelectItems(x.getSelectList(), SQLSetQuantifier.DISTINCT == x.getDistionOption());
	}

	if (x.getFrom() != null) {
		println();
		print0(ucase ? "FROM " : "from ");
		x.getFrom().accept(this);
	}

	if (x.getWhere() != null) {
		println();
		print0(ucase ? "WHERE " : "where ");
		x.getWhere().setParent(x);
		x.getWhere().accept(this);
	}

	if (x.getGroupBy() != null) {
		println();
		x.getGroupBy().accept(this);
	}

	if (x.getOrderBy() != null) {
		println();
		x.getOrderBy().accept(this);
	}

	if (rewriteDistinct) {
		print0(") ZebraDaoDistinctTable");
	}

	return false;
}
 

/**
     * 从between语句中获取字段所属的表名。
     * 对于容易出现ambiguous的（字段不知道到底属于哪个表），实际应用中必须使用别名来避免歧义
     * @param betweenExpr
     * @param column
     * @return
     */
    private String getOwnerTableName(SQLBetweenExpr betweenExpr,String column) {
        if(tableStats.size() == 1) {//只有一个表，直接返回这一个表名
            return tableStats.keySet().iterator().next().getName();
        } else if(tableStats.size() == 0) {//一个表都没有，返回空串
            return "";
        } else {//多个表名
            for (Column col : columns.keySet())
            {
                if(col.getName().equals(column)) {
                    return col.getTable();
                }
            }
//            for(Column col : columns) {//从columns中找表名
//                if(col.getName().equals(column)) {
//                    return col.getTable();
//                }
//            }

            //前面没找到表名的，自己从parent中解析

            SQLObject parent = betweenExpr.getParent();
            if(parent instanceof SQLBinaryOpExpr)
            {
                parent=parent.getParent();
            }

            if(parent instanceof MySqlSelectQueryBlock) {
                MySqlSelectQueryBlock select = (MySqlSelectQueryBlock) parent;
                if(select.getFrom() instanceof SQLJoinTableSource) {//多表连接
                    SQLJoinTableSource joinTableSource = (SQLJoinTableSource)select.getFrom();
                    return joinTableSource.getLeft().toString();//将left作为主表，此处有不严谨处，但也是实在没有办法，如果要准确，字段前带表名或者表的别名即可
                } else if(select.getFrom() instanceof SQLExprTableSource) {//单表
                    return select.getFrom().toString();
                }
            }
            else if(parent instanceof SQLUpdateStatement) {
                SQLUpdateStatement update = (SQLUpdateStatement) parent;
                return update.getTableName().getSimpleName();
            } else if(parent instanceof SQLDeleteStatement) {
                SQLDeleteStatement delete = (SQLDeleteStatement) parent;
                return delete.getTableName().getSimpleName();
            } else {
                
            }
        }
        return "";
    }
 

@Override
public SchemaConfig visitorParse(SchemaConfig schema, RouteResultset rrs, SQLStatement stmt,
                                 ServerSchemaStatVisitor visitor, ServerConnection sc, boolean isExplain) throws SQLException {
    SQLSelectStatement selectStmt = (SQLSelectStatement) stmt;
    SQLSelectQuery sqlSelectQuery = selectStmt.getSelect().getQuery();
    String schemaName = schema == null ? null : schema.getName();
    if (sqlSelectQuery instanceof MySqlSelectQueryBlock) {
        //check the select into sql is not supported
        MySqlSelectQueryBlock mysqlSelectQuery = (MySqlSelectQueryBlock) sqlSelectQuery;
        if (mysqlSelectQuery.getInto() != null) {
            throw new SQLNonTransientException("select ... into is not supported!");
        }

        //three types of select route according to the from item in select sql
        SQLTableSource mysqlFrom = mysqlSelectQuery.getFrom();
        if (mysqlFrom == null) {
            routeForNoFrom(schema, rrs, visitor, isExplain, sc, selectStmt);
            return schema;
        } else if (mysqlFrom instanceof SQLExprTableSource) {
            SQLExprTableSource fromSource = (SQLExprTableSource) mysqlFrom;
            SchemaInfo schemaInfo = SchemaUtil.getSchemaInfo(sc.getUser(), schemaName, fromSource);
            if (schemaInfo.isDual()) {
                //dual just route for a Random dataNode
                RouterUtil.routeNoNameTableToSingleNode(rrs, schema);
                return schema;
            } else if (SchemaUtil.MYSQL_SYS_SCHEMA.contains(schemaInfo.getSchema().toUpperCase())) {
                //sys_schema just use a special handler to response
                MysqlSystemSchemaHandler.handle(sc, schemaInfo, mysqlSelectQuery);
                rrs.setFinishedExecute(true);
                return schema;
            } else {
                //normal schema in config
                if (!ServerPrivileges.checkPrivilege(sc, schemaInfo.getSchema(), schemaInfo.getTable(), CheckType.SELECT)) {
                    String msg = "The statement DML privilege check is not passed, sql:" + stmt.toString().replaceAll("[\\t\\n\\r]", " ");
                    throw new SQLNonTransientException(msg);
                }
                super.visitorParse(schema != null ? schema : schemaInfo.getSchemaConfig(), rrs, stmt, visitor, sc, isExplain);
                //check to route for complex
                if (ProxyMeta.getInstance().getTmManager().getSyncView(schemaInfo.getSchemaConfig().getName(), schemaInfo.getTable()) != null ||
                        hasInnerFuncSelect(visitor.getFunctions())) {
                    rrs.setNeedOptimizer(true);
                    rrs.setSqlStatement(selectStmt);
                    return schemaInfo.getSchemaConfig();
                }
                if (visitor.getSubQueryList().size() > 0) {
                    return executeComplexSQL(schemaName, schema, rrs, selectStmt, sc, visitor.getSelectTableList().size(), visitor.isContainsInnerFunction());
                }

                //route for single table
                routeSingleTable(rrs, schemaInfo, mysqlSelectQuery, selectStmt, sc);
                return schema;
            }

        } else if (mysqlFrom instanceof SQLSubqueryTableSource ||
                mysqlFrom instanceof SQLJoinTableSource ||
                mysqlFrom instanceof SQLUnionQueryTableSource) {
            super.visitorParse(schema, rrs, stmt, visitor, sc, isExplain);
            return executeComplexSQL(schemaName, schema, rrs, selectStmt, sc, visitor.getSelectTableList().size(), visitor.isContainsInnerFunction());
        }
    } else if (sqlSelectQuery instanceof SQLUnionQuery) {
        super.visitorParse(schema, rrs, stmt, visitor, sc, isExplain);
        return executeComplexSQL(schemaName, schema, rrs, selectStmt, sc, visitor.getSelectTableList().size(), visitor.isContainsInnerFunction());
    }
    return schema;
}
 

private static boolean isJoin(SQLQueryExpr sqlExpr,String sql) {
    MySqlSelectQueryBlock query = (MySqlSelectQueryBlock) sqlExpr.getSubQuery().getQuery();
    return query.getFrom() instanceof SQLJoinTableSource && ((SQLJoinTableSource) query.getFrom()).getJoinType() != SQLJoinTableSource.JoinType.COMMA && sql.toLowerCase().contains("join");
}
 

private void findGroupBy(MySqlSelectQueryBlock query, Select select) throws SqlParseException {
    SQLSelectGroupByClause groupBy = query.getGroupBy();

    //modified by xzb group by 增加Having语法
    if (null != query.getGroupBy() && null != query.getGroupBy().getHaving()) {
        select.setHaving(query.getGroupBy().getHaving().toString());
    }

    SQLTableSource sqlTableSource = query.getFrom();
    if (groupBy == null) {
        return;
    }
    List<SQLExpr> items = groupBy.getItems();

    List<SQLExpr> standardGroupBys = new ArrayList<>();
    for (SQLExpr sqlExpr : items) {
        //todo: mysql expr patch
        if (sqlExpr instanceof MySqlOrderingExpr) {
            MySqlOrderingExpr sqlSelectGroupByExpr = (MySqlOrderingExpr) sqlExpr;
            sqlExpr = sqlSelectGroupByExpr.getExpr();
        }
        if ((sqlExpr instanceof SQLParensIdentifierExpr || !(sqlExpr instanceof SQLIdentifierExpr || sqlExpr instanceof SQLMethodInvokeExpr)) && !standardGroupBys.isEmpty()) {
            // flush the standard group bys
            // zhongshu-comment 先将standardGroupBys里面的字段传到select对象的groupBys字段中，然后给standardGroupBys分配一个没有元素的新的list
            select.addGroupBy(convertExprsToFields(standardGroupBys, sqlTableSource));
            standardGroupBys = new ArrayList<>();
        }

        if (sqlExpr instanceof SQLParensIdentifierExpr) {
            // single item with parens (should get its own aggregation)
            select.addGroupBy(FieldMaker.makeField(((SQLParensIdentifierExpr) sqlExpr).getExpr(), null, sqlTableSource.getAlias()));
        } else if (sqlExpr instanceof SQLListExpr) {
            // multiple items in their own list
            SQLListExpr listExpr = (SQLListExpr) sqlExpr;
            select.addGroupBy(convertExprsToFields(listExpr.getItems(), sqlTableSource));
        } else {
            // everything else gets added to the running list of standard group bys
            standardGroupBys.add(sqlExpr);
        }
    }
    if (!standardGroupBys.isEmpty()) {
        select.addGroupBy(convertExprsToFields(standardGroupBys, sqlTableSource));
    }
}