If you are not working with the default result set that EGL normally creates for this SQL record variable, specify a result set ID. Example The following example shows thedeletestatement for SQL: try get dept forUpdate; dept.description = "Test Engineers"; delete dept; commit(); onException...
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These SQL delete statements delete all the table’s data. Usually, we do not remove all the rows from a SQL table. To remove a specific row, we can add a where clause with the delete statement. The where clause contains the filter criteria and eventually determines which row(s) to remov...
了解语法定义是远远不够的,我们还需要看看parser.y对Delete Statement的MySQL实现,从Delete Statement开始,分成了DeleteWithoutUsingStmt和DeleteWithUsingStmt两个分支,每个分支中又定义了对应的语法,可以看出每一个语法定义都基本符合MySQL的定义,整个过程就是把SQL解析成AST,下一步就是拿现有的parser做个demo,看看是否能...
/**JDBC课程2--实现Statement(用于执行SQL语句)* 1.Statement :用于执行SQL语句的对象; * 1): 通过Connection 的createStatement()方法获取; * 2): 通过executeUpdate(sql) 可以执行SQL语句; * 3): 通过传入的sql 可以是insert、update或者delete ;但不能使select; ...
The DELETE statement (delete_statement) deletes rows from a table.Structure Syntax <delete_statement> ::= DELETE [FROM] [<reference_name>] [KEY <key_spec>,...] <! This SQL clause is no longer recommended to be used and might be removed from future versions. !> [WHERE <search_condi...
-- This SQL statement deletes rows from the newcate table where the cate_id is 'CA002' DELETE FROM newcate -- Specifies the condition for which rows to delete WHERE cate_id = 'CA002'; Explanation: The purpose of this SQL code is to delete rows from the newcate table where the cate...
s tStatement = ##class(%SQL.Statement).%New(0,"Sample") s qStatus = tStatement.%Prepare(sqltext) if qStatus'=1 { w "%Prepare failed:" d $System.Status.DisplayError(qStatus) q } s rtn = tStatement.%Execute("Fr") if rtn.%SQLCODE=0 { w !,"Delete succeeded" w !,"Row ...
我们还需要看看parser.y对Delete Statement的MySQL实现,从Delete Statement开始,分成了DeleteWithoutUsingStmt和DeleteWithUsingStmt两个分支,每个分支中又定义了对应的语法,可以看出每一个语法定义都基本符合MySQL的定义,整个过程就是把SQL解析成AST,下一步就是拿现有的parser做个demo,看看是否能正常解析我们的Delete SQL...
DELETEFROMordersWHEREorder_id =1;DELETEFROMorder_itemsWHEREorder_id =1;COMMITWORK;Code language:SQL (Structured Query Language)(sql) Note that theCOMMIT WORKstatement ensures bothDELETEstatements execute in a “all or nothing” manner, which prevents the orphaned rows in theorder_itemstable in cas...