ON Persons.Id_P=Orders.Id_P CREATE DATABASE 创建数据库语句 CREATE DATABASE database_name CREATE TABLE创建数据库中的表语句 语法 CREATE TABLE 表名称 ( 列名称1 数据类型, 列名称2数据类型, 列名称3 数据类型, ... ) 数据类型(data_type)规定了列可容纳何种数据类型。下面的表格包含了SQL中最常用的...
///利用反射和泛型将SqlDataReader转换成List模型 /// ///查询sql语句 ///<returns></returns> public IList<T> ExecuteToList<T>(string sql) where T : new() { IList<T> list; Type type = typeof (T); string tempName = string.Empty; using (SqlDataReader reader = ExecuteReader(sql)) {...
SET(val1, val2, val3, ...)A string object that can have 0 or more values, chosen from a list of possible values. You can list up to 64 values in a SET list Numeric Data Types Data typeDescription BIT(size)A bit-value type. The number of bits per value is specified insize. Th...
Number types let you store numeric data (integers, real numbers, and floating-point numbers), represent quantities, and do calculations. BINARY_INTEGER You use the BINARY_INTEGER datatype to store signed integers. Its magnitude range is -2**31 .. 2**31. BINARY_INTEGER values require less ...
The following is a list of the SQL types and their C/C++ language representations. It includes information on whether each type is valid as a parameter or a result. Also included are examples of how the types could appear as an argument definition in your C or C++ language routine: ...
data2int, primarykey(name,data2) )shardkey=name; 创建一级 Range|List 分区表: 使用场景: 一级分区除了根据 shardkey 进行一致性 hash 分区,也可以根据实际场景进行 Range 或 List 进行一级分区。 Range 分区是指根据一定字段取值范围进行分区指定,适合例如日志流水表,可以根据一定日期范围进行分区,方便后续数...
DBNull.Value : value;64Add(parameter);65returnparameter;66}6768///69///Creates a new SqlParameter instance and adds it to the list70///71///The name of the parameter72///The data type of the parameter73///The value of the parameter74///<returns>The new SqlParameter instance</returns...
importjava.sql.Connection;importjava.sql.PreparedStatement;importjava.sql.ResultSet;importjava.sql.SQLException;publicclassUserDao{publicList<User>findAll()throwsSQLException{List<User>users=newArrayList<>();Stringsql="SELECT id, name, email FROM users";try(Connectionconnection=DatabaseUtil.getConnection(...
DATABASE_NAME = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521)) ) (CONNECT_DATA = #(SERVICE_NAME = dealer) (SID = SID_NAME) #(SERVER = DEDICATED) ) ) 7. 关键字自动大写: 了解一点编程的常识的人都知道,编码风格很重要。 在阅读代码方面,...
/*#OPTIONS {"DynamicSQLTypeList":",1"} */ Parameter values: %CallArgs(1)=5 %CallArgs(2)="Fred" 事件数据的总长度(包括语句和参数)为3,632,952个字符。如果该语句和参数长于3632952,则事件数据将被截断。 InterSystems IRIS还支持ODBC和JDBC语句的审核(事件名称= XDBCStatement),以及嵌入式SQL语句的...