面試題-數(shù)據(jù)庫試題

一.單選、下列SQLA、 修改表結(jié) 更新表數(shù)D、 錄入表數(shù)Update表名setUpdate表名set字段名稱=字段值,zd1=v1.... 條A、updateintousersetidB、updateusersetid'u001andusername='jack';C、updateusersetusername='jack'whereid=1;D、updateintousersetidu001',、用戶表user中存在一個(gè)字段username,查詢名字包含"鳳"（不考慮位置A、select*fromuserwhereusername鳳B、select*fromuserwhereusernamelike鳳%';C、select*fromuserwhereusernamelike'_鳳_';D、select*fromuserwhereusernamelike'鳳';第一頁第一頁：limit --- 格式：limit開始索引,每頁顯示的個(gè)A、select*fromtestlimit10,10;B、select*fromtestlimit11,10;C、select*fromtestlimit10,20;D、select*fromtestlimit、用戶表usersage和countint | | |count |u001 18 60 執(zhí)行“selectagecountfromuserswhereid'u001';”結(jié)果為？UpdateaccountUpdateaccountsetmoney=money+ 二.多選BnullC、主鍵必須在創(chuàng)建表是指定(3種)D、sql語句主鍵預(yù)留的關(guān)鍵為：primaryA、外鍵是為了保證從表與主表之間的數(shù)據(jù)一致性和完整性（關(guān)系BnullC、性Djava A、starttransaction;開啟事務(wù)Bjava C、rollback;D、delete;三.簡答*本題中的數(shù)據(jù)庫database的名稱獲得:4個(gè)用戶名 例：1234 Statement對象查詢所有數(shù)據(jù)，打印到控制臺獲得Connectionconn=Statementst=sqlStringsql=“selectid,title,pricefrombooks”;ResultSetrs=st.executeQuery(sql);while(rs.next()getString(String字段 索引getString(String字段 索引號從1開始Doubleprice=rs.getDouble(“price”);syso…}使用PreparedStatement對象錄入(b004,ssh,125) Connectionconn …省略1sqlStringsql=“insertintobooks(id,title,price)2PreparedStatementpsmt=//3設(shè)置內(nèi)容4intrpstm.executeUpdatesqlif(r>}else}//5資roles into`privileges`(`id`,`privilegename`,`description`,`url`)values('p001','添加','具有錄入的功能','/functions/addBook.jsp'),('p002','查詢','查詢查詢查詢查詢('p003','更新','更新更新更新更新','/functions/updateBook.jsp'),('p004','刪除','刪除刪除刪除','/functions/deleteBook.jsp'); into`roles`(`id`,`rolename`,`description`valuessqlsql查詢權(quán)限表rolename1.sqlsql并提供至少兩個(gè)字段，一個(gè)是rolesprivileges#createtableprivileges(idvarchar(32),privilegenamevarchar(50),descriptionvarchar(200),urlvarchar(200)#createtableroles(idrolenamevarchar(50),descriptionvarchar(200) into`privileges`(`id`,`privilegename`,`description`,`url`values('p001','添加','具有錄入的功能','/functions/addBook.jsp'),('p002','查詢','查詢查詢查詢查詢','/functions/findBook.jsp'),('p003','更新','更新更新更新更新','/functions/updateBook.jsp'),('p004','刪除','刪除刪除刪除','/functions/deleteBook.jsp'); into`roles`(`id`,`rolename`,`description`values##createtableroles_id #privileges_idvarchar(32)####1.rolesaltertablerolesaddconstraintprimarykeyid);#2.roles對應(yīng)外鍵altertableroles_privilegesaddconstraintforeignkey(roles_id)references3privilegesaltertableprivilegesaddconstraintprimarykey(id);#4privileges對應(yīng)外鍵altertableroles_privilegesaddconstraintforeignkey(privileges_id)referencesselect權(quán)限表rolenameinsertintoroles_privileges(roles_id,privileges_id)values('r001','p001');insertintoroles_privileges(roles_id,privileges_id)values('r001','p002');insertintoroles_privileges(roles_id,privileges_id)values('r001','p003');insertintoroles_privileges(roles_id,privileges_id)values('r001','p004');insertintoroles_privileges(roles_id,privileges_id)values('r002','p001');insertintoroles_privileges(roles_id,privileges_id)values('r002','p003');selectprivileges.*fromprivileges,roles_privileges,whereprivileges.idroles_privileges.privileges_id