在PostgreSQL中,LIKE 运算符通常用于搜索列中的特定模式,但它并不直接支持多个值的匹配。如果你需要匹配多个值或模式,有几种方法可以实现这一点。 方法一:使用 OR 连接多个 LIKE 条件 这是最直接的方法,通过 OR 将多个 LIKE 条件连接起来。例如,如果你想在一个名为 employees 的表中查找名字以 "A" 或 "B"...
Not-null constraints are always copied to the new table. CHECK constraints will be copied only if INCLUDING CONSTRAINTS is specified. Indexes, PRIMARY KEY, and UNIQUE constraints on the original table will be created on the new table only if the INCLUDING INDEXES clause is specified. No distinct...
PRIMARY KEY, and UNIQUE constraints on the original table will be created on the new table only if the INCLUDING INDEXES clause is specified. No distinction is made between column constraints and table constraints.
Not-null constraints are always copied to the new table. CHECK constraints will be copied only if INCLUDING CONSTRAINTS is specified. Indexes, PRIMARY KEY, and UNIQUE constraints on the original table will be created on the new table only if the INCLUDING INDEXES clause is specified. No distinct...
The WHERE clause in the query contains an expression: first_name LIKE 'Jen%' The expression consists of the first_name, the LIKE operator and a literal string that contains a percent sign (%). The string 'Jen%' is called a pattern. The query returns rows whose values in the first_name...
The LIKE clause specifies a table from which the new table automatically copies all column names, their data types, and their not-null constraints. 如上所示,当使用LIKE子句做表复制时,默认会自动拷贝所有字段、字段类型以及它们的NOT-NULL约束,这也就解释了刚才为什么会成功复制NOT-NULL约束。
//www.runoob.com/mysql/mysql-where-clause.html1、WHERE 子句1.1、语法SELECT field1, field2,...fieldN...、作用修改或更新 MySQL 中的数据2.2、语法UPDATE table_name SET field1=new-value1, field2=new-value2[WHERE Clause]你可以同时更新一个或多个字段...你可以在一个单独表中同时更新数据。....
By using the escape clause, you can ensure that your LIKE expressions work correctly even when the search string contains special characters. Case Sensitivity in LIKE Query By default, most databases are case-insensitive when performing LIKE queries. This means that if you search for “john” usi...
hqlBuilder.addWhereClause(" concat(this.user.name,this.ip,this.mac,this.name,this.organization.name) like ? ","%"+queryBean.getConditions()+"%"); } 一、LIKE 操作符用于在 WHERE 子句中搜索列中的指定模式。 语法:SELECT column_name(s)FROM table_nameWHERE column_nameLIKE pattern; ...
clause: str/obj类型,可以传入原生SQL语句字符串(与适配器相同),或者条件表达式 params: dict/list of dict类型,传入单个字典时,使用适配器execute,多个executemany,参考适配器部分内容 返回参数: re re: obj类型,返回的结果,ResultProxy结果代理类,可从中获取信息 ...