Delete

How do I use Delete
Below are practical examples compiled from projects for learning and reference purposes

Featured Snippets

Line	Code	Ex..
91	da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");	1
136	da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");	2
186	da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");	3
297	da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");	4
312	public void Delete(string table, string sql)	5
64	business.Delete("GiangVien", sql);	6
61	business.Delete("HeDaoTao", sql);	7
47	business.Delete("HocKy", sql);	8
48	business.Delete("HocPhan", sql);	9
58	business.Delete("KeHoachGiangDay", sql);	10

File name: ClassBLL.cs Copy

83         public DataTable XemDiemLop(string MaLop)
84         {
85             SqlConnection con = new SqlConnection();
86             ChuanBi3Table();
87             string sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
88                           " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
89                             " where MaLop='" + MaLop + "'";
90             DataTable dt4 = da.GetTable(sql4);
91             da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");
92             da.ExcuteNonQuery("delete from Lopdiem10 where MaSV in ( select MaSV from Lopdiem10 )");
93             da.ExcuteNonQuery("delete from DTB where MaSV in ( select MaSV from DTB )");
94             return dt4;
95         }

File name: ClassBLL.cs Copy

96         public DataTable ThongKeLop(string MaHK,string MaLop,int loai)
97         {
98             SqlConnection con = da.GetConnect();
99             ChuanBi3Table(MaHK);
100             //Truy van cuoi cung
101             string sql4;
102             switch (loai)
103             {
104                 case 0:
105                     sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
106                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
107                            " where MaLop='" + MaLop + "' and TrungBinhCuoiKyHe10 >= 9";
108                     break;
109                 case 1:
110                     sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
111                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
112                            " where MaLop='" + MaLop + "' and TrungBinhCuoiKyHe10 >=8 and TrungBinhCuoiKyHe10 < 9";
113                     break;
114                 case 2:
115                     sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
116                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
117                            " where MaLop='" + MaLop + "' and TrungBinhCuoiKyHe10 >=6.5 and TrungBinhCuoiKyHe10 < 8";
118                     break;
119                 case 3:
120                     sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
121                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
122                            " where MaLop='" + MaLop + "' and TrungBinhCuoiKyHe10 >=5 and TrungBinhCuoiKyHe10 < 6.5";
123                     break;
124                 case 4:
125                     sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
126                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
127                            " where MaLop='" + MaLop + "' and TrungBinhCuoiKyHe10 >=3.5 and TrungBinhCuoiKyHe10 < 5";
128                     break;
129                 default:
130                     sql4 = "select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 " +
131                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV " +
132                            " where MaLop='" + MaLop + "' and TrungBinhCuoiKyHe10 < 3.5";
133                     break;
134             }
135             DataTable dt4 = da.GetTable(sql4);
136             da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");
137             da.ExcuteNonQuery("delete from Lopdiem10 where MaSV in ( select MaSV from Lopdiem10 )");
138             da.ExcuteNonQuery("delete from DTB where MaSV in ( select MaSV from DTB )");
139             return dt4;
140         }

File name: ClassBLL.cs Copy

141         public DataTable ThongKeKhoiLop(string MaHK, string MaKhoiLop, int loai)
142         {
143             SqlConnection con = da.GetConnect();
144             ChuanBi3Table(MaHK);
145             string sql4;
146             switch (loai)
147             {
148                 case 0:
149                     sql4 = "select sv.MaSV,TenSV,sv.MaLop,TrungBinhCuoiKyHe10 " +
150                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV,KhoiLop kl,Lop l " +
151                            " where sv.MaLop=l.MaLop and l.MaKhoiLop=kl.MaKhoiLop " +
152                            " and kl.MaKhoiLop='" + MaKhoiLop + "' and TrungBinhCuoiKyHe10 >=9 ";
153                     break;
154                 case 1:
155                     sql4 = "select sv.MaSV,TenSV,sv.MaLop,TrungBinhCuoiKyHe10 " +
156                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV,KhoiLop kl,Lop l " +
157                            " where sv.MaLop=l.MaLop and l.MaKhoiLop=kl.MaKhoiLop " +
158                            " and kl.MaKhoiLop='" + MaKhoiLop + "' and TrungBinhCuoiKyHe10 >=8 and TrungBinhCuoiKyHe10 < 9";
159                     break;
160                 case 2:
161                     sql4 = "select sv.MaSV,TenSV,sv.MaLop,TrungBinhCuoiKyHe10 " +
162                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV,KhoiLop kl,Lop l " +
163                            " where sv.MaLop=l.MaLop and l.MaKhoiLop=kl.MaKhoiLop " +
164                            " and kl.MaKhoiLop='" + MaKhoiLop + "' and TrungBinhCuoiKyHe10 >=6.5 and TrungBinhCuoiKyHe10 < 8";
165                     break;
166                 case 3:
167                     sql4 = "select sv.MaSV,TenSV,sv.MaLop,TrungBinhCuoiKyHe10 " +
168                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV,KhoiLop kl,Lop l " +
169                            " where sv.MaLop=l.MaLop and l.MaKhoiLop=kl.MaKhoiLop " +
170                            " and kl.MaKhoiLop='" + MaKhoiLop + "' and TrungBinhCuoiKyHe10 >=5 and TrungBinhCuoiKyHe10 < 6.5";
171                     break;
172                 case 4:
173                     sql4 = "select sv.MaSV,TenSV,sv.MaLop,TrungBinhCuoiKyHe10 " +
174                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV,KhoiLop kl,Lop l " +
175                            " where sv.MaLop=l.MaLop and l.MaKhoiLop=kl.MaKhoiLop " +
176                            " and kl.MaKhoiLop='" + MaKhoiLop + "' and TrungBinhCuoiKyHe10 >=3.5 and TrungBinhCuoiKyHe10 < 5";
177                     break;
178                 default:
179                     sql4 = "select sv.MaSV,TenSV,sv.MaLop,TrungBinhCuoiKyHe10 " +
180                            " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV,KhoiLop kl,Lop l " +
181                            " where sv.MaLop=l.MaLop and l.MaKhoiLop=kl.MaKhoiLop " +
182                            " and kl.MaKhoiLop='" + MaKhoiLop + "' and TrungBinhCuoiKyHe10 < 3.5";
183                     break;
184             }
185             DataTable dt4 = da.GetTable(sql4);
186             da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");
187             da.ExcuteNonQuery("delete from Lopdiem10 where MaSV in ( select MaSV from Lopdiem10 )");
188             da.ExcuteNonQuery("delete from DTB where MaSV in ( select MaSV from DTB )");
189             return dt4;
190         }

File name: ClassBLL.cs Copy

289         public DataTable XemDiemLop(string MaHK,string MaLop)
290         {
291             SqlConnection con = new SqlConnection();
292             ChuanBi3Table(MaHK);
293             string sql4="select sv.MaSV,TenSV,TrungBinhCuoiKyHe10 "+
294                           " from DTB left join SinhVien sv on DTB.MaSV=sv.MaSV "+
295                             " where MaLop='"+MaLop+"'";
296             DataTable dt4 = da.GetTable(sql4);
297             da.ExcuteNonQuery("delete from Loptc where MaSV in ( select MaSV from Loptc )");
298             da.ExcuteNonQuery("delete from Lopdiem10 where MaSV in ( select MaSV from Lopdiem10 )");
299             da.ExcuteNonQuery("delete from DTB where MaSV in ( select MaSV from DTB )");
300             return dt4;
301         }

File name: ClassBLL.cs Copy

312         public void Delete(string table, string sql)
313         {
314             sql = "delete from "+table+" where "+sql+"";
315             da.ExcuteNonQuery(sql);
316         }

File name: FormGiangVien.cs Copy

57         private void btnXoa_Click(object sender, EventArgs e)
58         {
59             DialogResult result;
60             result = MessageBox.Show("Bạn có chắc chắn muốn xóa không ?","Hệ Thống", MessageBoxButtons.YesNo);
61             if (result == DialogResult.Yes)
62             {
63                 string sql = "MaGV='" + txtMaGV.Text + "'";
64                 business.Delete("GiangVien", sql);
65                 FormGiangVien_Load(sender, e);
66             }
67         }

File name: FormHeDaoTao.cs Copy

54         private void btnXoa_Click(object sender, EventArgs e)
55         {
56             DialogResult result;
57             result = MessageBox.Show("Bạn có chắc chắn muốn xóa không ?","Hệ Thống", MessageBoxButtons.YesNo);
58             if (result == DialogResult.Yes)
59             {
60                 string sql = "MaHeDT = '" + txtMaHeDT.Text + "'";
61                 business.Delete("HeDaoTao", sql);
62                 FormHeDaoTao_Load(sender, e);
63             }
64         }

File name: FormHocKy.cs Copy

40         private void btnXoa_Click(object sender, EventArgs e)
41         {
42             DialogResult result;
43             result = MessageBox.Show("Bạn có chắc chắn muốn xóa không ?","Hệ Thống", MessageBoxButtons.YesNo);
44             if (result == DialogResult.Yes)
45             {
46                 string sql = "MaHK='" + txtMaHocKy.Text + "'";
47                 business.Delete("HocKy", sql);
48                 FormHocKy_Load(sender, e);
49             }
50         }

File name: FormHocPhan.cs Copy

41         private void btnXoa_Click(object sender, EventArgs e)
42         {
43             DialogResult result;
44             result = MessageBox.Show("Bạn có chắc chắn muốn xóa không ?","Hệ Thống", MessageBoxButtons.YesNo);
45             if (result == DialogResult.Yes)
46             {
47                 string sql = "MaHP='" + txtMaHP.Text + "'";
48                 business.Delete("HocPhan", sql);
49                 FormHocPhan_Load(sender, e);
50             }
51         }

File name: FormKHGD.cs Copy

51         private void btnXoa_Click(object sender, EventArgs e)
52         {
53             DialogResult result;
54             result = MessageBox.Show("Bạn có chắc chắn muốn xóa không ?", "Hệ Thống", MessageBoxButtons.YesNo);
55             if (result == DialogResult.Yes)
56             {
57                 string sql = "MaKHGD='" + txtMaKHGD.Text + "'";
58                 business.Delete("KeHoachGiangDay", sql);
59                 FormKHGD_Load(sender, e);
60             }
61         }

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