【发布时间】:2021-01-23 11:34:53
【问题描述】:
我正在尝试通过 JSP 从我的整个 MySQL 数据库中实现 keyword search,如果我选择的方法效率低下,我会感到困惑:(
我已经阅读了information_schema 并发现所有列标签都在那里。
我已经尝试了下面的 SQL 语句来生成所有可能的查询:
SELECT CONCAT('SELECT * FROM ',table_schema,'.',table_name,
' WHERE ',column_name,' LIKE ','searchString',';')
FROM information_schema.columns
WHERE table_schema NOT IN ('information_schema','mysql','performance_schema')
AND (column_type LIKE 'char(%'
OR column_type LIKE 'varchar(%'
OR column_type LIKE '%text')
并尝试使用 JSP 代码来获得所有可能的数据匹配。
<%
String searchString = "malayalam";
searchString = "''%"+searchString+"%'' ";
ArrayList<String> queries = new ArrayList<String>();
String sql="SELECT CONCAT('SELECT * FROM ',table_schema,'.',table_name,"
+ "' WHERE ',column_name,' LIKE ','"+searchString+"',';')"
+ "FROM information_schema.columns "
+ "WHERE table_schema NOT IN ('information_schema','mysql','performance_schema')"
+ "AND (column_type LIKE 'char(%'"
+ "OR column_type LIKE 'varchar(%'"
+ "OR column_type LIKE '%text')";
try{
DBConInfoSchema db = new DBConInfoSchema();
ResultSet rs = db.getData(sql);
while(rs.next()){
queries.add(rs.getString(1));
}
for(int i=0;i<queries.size();i++){
DBConInfoSchema dCon = new DBConInfoSchema();
ResultSet rsDemo = dCon.getData(queries.get(i));
if(rsDemo.next()){
out.print("<br/>Data found n query-"+i+" -> "+queries.get(i));
}
dCon.DBClose();
}
}catch(Exception w){
out.print("excep<br/>"+w);
}
%>
现在我得到了巨大的查询列表。 我很困惑它是好是坏?! 考虑到效率,这种方法是不是很糟糕?
【问题讨论】:
标签: java mysql jsp keyword-search