having problem in Select statement

[shamaila]

in my windows form,for search,two combo boxes are provided.the first one gives the table names and in second combo box the respective fields are provided ,by selecting any field the user enters the required value according to which te search is done

i m storing both tablename and field name in string
now in my select statement when i append the string with field name (with hard coded table name); it functions well but when i concatenate string having table name it gives errors..

[gagandeepgupta16]

in my windows form,for search,two combo boxes are provided.the first one gives the table names and in second combo box the respective fields are provided ,by selecting any field the user enters the required value according to which te search is done

i m storing both tablename and field name in string
now in my select statement when i append the string with field name (with hard coded table name); it functions well but when i concatenate string having table name it gives errors..

could you please paste the part of the code?

you need to take care of datatype of the comparing (condition) field

string str = "select * from " + ddltablename + " where "+ ddlfieldname "='" + fieldvalue +"' ";

this one was for varchar type condition variable. where as for numeric type condition value it will be ......ddlfieldname "=" + fieldvalue;

[shamaila]

could you please paste the part of the code?

you need to take care of datatype of the comparing (condition) field

string str = "select * from " + ddltablename + " where "+ ddlfieldname "='" + fieldvalue +"' ";

this one was for varchar type condition variable. where as for numeric type condition value it will be ......ddlfieldname "=" + fieldvalue;

if(combobox2.text==" teachers name")
str="t_name"; //giving field name
//many if statements here

strQuery = " SELECT * FROM tbl1,tbl2,tbl3 WHERE tbl1." + str + "=" + textBox1.Text+"AND

tbl1.t_id=tbl2.tb_id AND tbl.t_id=tbl3.tb3_id ";

it works
but when i do

//tablename=combobox1.text;
//or
tablename="tbl1";

strQuery = " SELECT * FROM tbl1,tbl2,tbl3 WHERE" + tablename + "." + str + "=" + textBox1.Text+"AND tbl1.t_id=tbl2.tb_id AND tbl.t_id=tbl3.tb3_id ";

it gives error

[gagandeepgupta16]

if(combobox2.text==" teachers name")
str="t_name"; //giving field name
//many if statements here

strQuery = " SELECT * FROM tbl1,tbl2,tbl3 WHERE tbl1." + str + "=" + textBox1.Text+"AND

tbl1.t_id=tbl2.tb_id AND tbl.t_id=tbl3.tb3_id ";

it works
but when i do

//tablename=combobox1.text;
//or
tablename="tbl1";

strQuery = " SELECT * FROM tbl1,tbl2,tbl3 WHERE" + tablename + "." + str + "=" + textBox1.Text+"AND tbl1.t_id=tbl2.tb_id AND tbl.t_id=tbl3.tb3_id ";

it gives error

if the above posted query is exact one then it requires a space after where clause, also if you can mind the space given before first "AND".

try if it helps you, or if you can also paste the error.