Statement stmt=null;try{//a.导入驱动,加载具体的驱动类Class.forName("oracle.jdbc.OracleDriver");//加载具体的驱动类//b.与数据库建立连接connection =DriverManager.getConnection(URL, USERNAME, PWD);//c.发送sql,执行(增删改、查)stmt =connection.createStatement();//String sql = "insert into student ...
动态 SQL 之<foreach> 循环执行sql的拼接操作，例如：SELECT * FROM USER WHERE id IN (1,2,5)。
非空约束:SQL允许表中列的值为null(空值) ,有的不允许为null,在后面紧跟关键字 not null 向表中添加数据: insert into table(column_name1,column_name2,...) values (column_value1,column_value2,...) 给某个字段指定缺省值:关键字Default <column_name><data_type> default <default_value> 2、表的...
statement.values.ValuesStatement; import net.sf.jsqlparser.util.TablesNamesFinder; import org.apache.commons.collections.CollectionUtils; import sun.net.www.content.text.plain; import java.util.List; import java.util.Objects; public class Main { static String sql1 = "select t1.f1,t1.f2,t2.id...
sql_statement_recompile扩展事件 (XEvent) 报告语句级重新编译。 当任何类型的批处理需要语句级重新编译时,会发生此 XEvent。 这包括存储过程、触发器、即席批处理和查询。 可通过几个接口来提交批处理,这类接口包括 sp_executesql、动态 SQL、“准备”方法或“执行”方法。
CASE WHEN is like an IF statement in a programming language. It is useful when we need to calculate a statistic on a certain subset of the data. In the image above, I calculate an average price for products sold in the US. I wasn’t careful with the ELSE in the CASE WHEN. ...
LIKE_REGEX SPACE CARDINALITY LIMIT SPECIFIC CASCADED LN SPECIFICTYPE CAST LOCAL SQL CATALOG LOCALTIME SQLEXCEPTION CHAR LOCALTIMESTAMP SQLSTATE CHARACTER LOCATOR SQLWARNING CLASS MAP START CLOB MATCH STATE COLLATION MEMBER STATEMENT COLLECT METHOD
Null(版本 8.4+)指定要使用的自定义套接字工厂的类名,而不是默认套接字工厂。 socketTimeout int 0在套接字读取或接受发生超时之前要等待的毫秒数。 默认值为 0,表示无期限超时。 statementPooling... 缓存大小 int 0(版本 6.4+)此属性可用于在驱动程序中启用准备的语句句柄缓存。
SQL_MAX_STATEMENT_LEN SQL_MAX_TABLE_NAME_LEN SQL_MAX_TABLES_IN_SELECT SQL_MAX_USER_NAME_LEN 标量函数信息 InfoType 参数的以下值返回有关数据源和驱动程序支持的标量函数的信息。 有关标量函数的详细信息,请参阅 附录E:标量函数。 SQL_CONVERT_FUNCTIONS SQL_NUMERIC_FUNCTIONS SQL_STRING_FUNCTIONS SQL_SYS...
A year ago I wrote about the pitfalls ofNULL values in NOT INsubqueries. This time I wanted to keep promises I made back then, dig a little deeper and also look at NOT EXISTS as another type of subquery used to filter out records based on negative matches. Is there any semantic differe...