sql 文本如下: select * from emp where empno > 5 and gender = 'F' Parser.jj(语法定义文件)和类 SqlParserImpl 中的 SqlSelect...一、方法声明 会根据 SqlSelect SqlSelect() 生成 final public SqlSelect SqlSelect() throws ParseException 规则也很简单:头加...这部分代码的作用是声明用于声明一些局部变量,这些局部变量会通过后续的 Token 解析和代码调用来赋值,最终用于构造 SqlSelect 2.2、代码调用 如下箭头所指即语法定义中的代码调用被直接复制到...throw generateParseException(); } } 举几个例子,比如: 会生成 jj_consume_token(SELECT) 代码,在 SqlSelect
if(SqlKind.SELECT.equals(sqlNode.getKind())){ SqlSelect sqlSelect = (SqlSelect) sqlNode; SqlNode...from=sqlSelect.getFrom(); SqlNode where=sqlSelect.getWhere(); SqlNodeList selectList=sqlSelect.getSelectList...sqls = new SqlSelect(sqlParserPos,null,snl,o,null,null,null,null,null,null,null); System.out.println...sqlSelect = (SqlSelect) sqlNode; SqlNode from=sqlSelect.getFrom(); SqlNode...where=sqlSelect.getWhere(); SqlNodeList selectList=sqlSelect.getSelectList();
作用 + 求两个数的和 - 求两个数的差 * 求两个数的乘 / 求两个数的除法,结果是小数 % 求模运算 注意: 当有字符串相加的时候,字符串当作0来处理 对于有NULL参与的运算结果都是NULL sqlSELECT...sqlSELECT NULL=NULL,NULLNULL FROM DUAL 非符号类运算符 IS NULL 是否为空 IS NOT NULL 是否不为空 LEAST 返回最小值 GREATEST...返回最大值 BETWEEN AND 两者之间的范围,左闭右闭 IN 判断值是否在表格内 LIKE 模糊匹配 正则表达式,暂时不写 例: sqlSELECT NULL IS NULL FROM DUAL...sqlSELECT salary FROM employees WHERE salary BETWEEN 3300 AND 6000 sqlSELECT last_name, salary FROM...employees WHERE salary IN (3000,3300,4000); sqlSELECT last_name FROM employees #查询last_name含有a的字符串 WHERE
calcite解析之后,得到一棵抽象语法树,也就是我们说的AST,这棵语法树是由不同的节点组成,节点称之为SqlNode,根据不同类型的dml、ddl得到不同的类型的SqlNode,例如select语句转换为SqlSelect...if(SqlKind.SELECT.equals(sqlNode.getKind())){ SqlSelect sqlSelect = (SqlSelect) sqlNode; SqlNode...from=sqlSelect.getFrom(); SqlNode where=sqlSelect.getWhere(); SqlNodeList selectList=sqlSelect.getSelectList...SqlKind是一个枚举类型,包含了各种SqlNode类型:SqlSelect、SqlIdentifier、SqlLiteral等。...SqlSelect/SqlDelete/SqlBasicCall 都称之为SqlCall,差别是SqlSelect是复杂的SqlCall,内部可以包含其他节点,而SqlBasicCall表示简单的SqlCall
而我们常见的各种SQL类型,都是继承了SqlCall,例如select查询,对应的是SqlSelect;create、drop等ddl,对应的是SqlDdl等。...这里我们看下一个SqlSelect的组成: 可以看到一个SqlSelect的parse tree主要包含了select list、from、where等部分,每个部分又由其各自的成员组成。...例如,对于常见的SqlSelect,其unparse方法的主要逻辑就是调用指定SqlDialect的unparseCall方法,如下所示: //SqlSelect.java @Override public...在处理完当前这个节点之后(例如SqlSelect),unparseCall方法就会调用这个节点的operator的unparse方法,如下所示: //SqlDialect.java public void...):227 ---unparseCall(SqlDialect.java):460 ---unparse(SqlSelectOperator.java):209 group by子句是属于SqlSelect
; Statement s = c.createStatement();) { // 不同1:execute可以执行查询语句 // 然后通过getResultSet,把结果集取出来 String sqlSelect...= “select * from hero”; s.execute(sqlSelect); ResultSet rs = s.getResultSet(); while (rs.next()) {...System.out.println(rs.getInt(“id”)); } // executeUpdate不能执行查询语句 // s.executeUpdate(sqlSelect); // 不同2...// execute返回boolean类型,true表示执行的是查询语句,false表示执行的是insert,delete,update等等 boolean isSelect = s.execute(sqlSelect
= nil { fmt.Println(err) return } defer db.Close() update(db) sqlselect(db) insert(db) fmt.Println...("插入后") sqlselect(db) delete(db); fmt.Println("删除后") sqlselect(db) } // 查询 数据 func sqlselect(db
SqlParser.configBuilder().setLex(Lex.MYSQL).build(); SqlParser sqlParser = SqlParser.create(sql, config); SqlSelect...sqlSelect = null; try { sqlSelect = (SqlSelect) sqlParser.parseStmt(); }...catch (Exception e) { e.printStackTrace(); } SqlNode sqlFrom = sqlSelect.getFrom...SqlParserPos(0, 0); SqlIdentifier sqlIdentifier = new SqlIdentifier(newName, pos); sqlSelect.setFrom
cx_Oracle.makedsn('127.0.0.1', '1534', 'dsn') db = cx_Oracle.connect('username', 'password', tns) def sqlSelect...= " " sql_2 = " " sql_3 = " " sql_list = [sql_1, sql_2, sql_3] for sql in sql_list: result = sqlSelect
DISTINCT的查询进行SQL构造 //---对含有DISTINCT的总数查询进行SQL构造 string strTmp = "", SqlSelect...= "", SqlCounts = ""; if (_Dist == 0) { SqlSelect...} if (_strCondition == string.Empty) { strTmp = SqlSelect...FROM " + _tbName; } else { strTmp = SqlSelect...primaryKey, strTop, tableName, strWhere, strOrderBy); strTmp = String.Format(SqlSelect
import logger import math class UserDAO(BaseDAO): #注册查重验证 def GetSameInfo(self,user): sqlSelect...user.telphone,) try: super().getConnection() result = super().fetchone(sqlSelect...() return result except Exception as e: logger.error("执行SQL:" + str(sqlSelect...)) finally: super().close() #登录验证 def GetLoginInfo(self,user): sqlSelect...() return result except Exception as e: logger.error("执行SQL:" + str(sqlSelect
将 student 中 id = 2 的 age 重新 set 为 22 String sqlDelete = "delete from student"; // 删除操作 String sqlSelect...sqlInsert2); st.execute(sqlUpdate); st.executeUpdate(sqlDelete); ResultSet rs = st.executeQuery(sqlSelect
golang 查询数据后,获取内容出错问题 panic: sql: expected 2 destination arguments in Scan, not 1 select 函数如下: func sqlSelect...log.Fatalln(err) } fmt.Println("a = ", a,"b = ", b ) } 解决方式二 如果字段比较多,有不想硬编码,可以使用下面的方式 func sqlSelect
例如 SqlSelect 类型,代码如下: 1: /// 2: /// 表示一个 Sql 查询语句。...3: /// 4: class SqlSelect : SqlNode 5: { 6: private IList _orderBy; 7:...8: public override SqlNodeType NodeType 9: { 10: get { return SqlNodeType.SqlSelect...TestMethod] 2: public void ORM_SqlTree_Select_InSubSelect() 3: { 4: var select = new SqlSelect...5: var articleTable = new SqlTable { TableName = "Article" }; 6: var subSelect = new SqlSelect
*/ –存储过程 create or replace procedure sp_Page(p_PageSize int, --每页记录数 p_PageNo int, --当前页码,从 1 开始 p_SqlSelect...v_heiRownum - p_PageSize + 1; v_sql := 'SELECT B.* FROM (SELECT A.*, rownum rn FROM ('|| p_SqlSelect
sqlSELECT primary_key_column, COUNT(*) FROM table_name GROUP BY primary_key_column HAVING COUNT(*)
DECLARE @SqlRecordCount NVARCHAR(100) -- The SQL Statement to get the total count of the records DECLARE @SqlSelect...SET @PageCount = @RecordCount / @PageSize ELSE SET @PageCount = @RecordCount / @PageSize + 1 SET @SqlSelect...tempid BETWEEN ' + STR((@PageIndex - 1)*@PageSize + 1) + ' AND ' + STR(@PageIndex * @PageSize) EXEC(@SqlSelect
import com.baomidou.mybatisplus.toolkit.StringUtils; //導入方法依賴的package包/類 /** * * SQL 設置selectObj sqlselect...TableInfo table) { StringBuilder columns = new StringBuilder(); /* * 普通查詢 */ columns.append(“${ew.sqlSelect...= table.getResultMap()) { /* * 存在 resultMap 映射返回 */ if (entityWrapper) { columns.append(“${ew.sqlSelect...= table.getResultMap()) { /* * 存在 resultMap 映射返回 */ if (entityWrapper) { columns.append(“${ew.sqlSelect...) { if (StringUtils.isNotEmpty(sqlSelect)) { this.sqlSelect = sqlSelect; } return this; } 開發者ID:baomidou
BY FieldB) AS FieldBs FROM TableName GROUP BY FieldA ORDER BY FieldA;SQLServerSQLServer≥2017&Azure SQLSELECT
以下是一个优化的示例:未优化sqlSELECT * FROM bus_work_order_operate_info ORDER BY OPERATE_TIME DESC LIMIT 10 OFFSET...5000;查询分析图片优化后sqlselect T1.* from bus_work_order_operate_info T1 INNER JOIN (select ID FROM bus_work_order_operate_info
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