sql server - How to insert multiple records into database with SqlParameter in C# -

i trying run following code:

using (sqlconnection conn = new sqlconnection(connstr)) {     conn.open();      stringbuilder sqlstr = new stringbuilder("insert customers values ( @name, @address, @city, @state)");      sqlcommand cmd = new sqlcommand(sqlstr.tostring(), conn);     cmd.parameters.add(new sqlparameter("@name", "john smith"));     cmd.parameters.add(new sqlparameter("@address", "123 main st."));     cmd.parameters.add(new sqlparameter("@city", "detroit"));     cmd.parameters.add(new sqlparameter("@state", "michigan"));      cmd.executereader();      cmd.parameters["@name"].value = "william jones";     cmd.parameters["@address"].value = "500 blanchard ave";     cmd.parameters["@city"].value = "chicago";     cmd.parameters["@state"].value = "illinois";      cmd.executereader(); } 

however, getting error. have tried multiple other ways, nothing seems work. proper way insert multiple records using sqlparameters?

first of cmd.executereader(); used on data retrieval , not not proper way in doing insert.

use

cmd.executenonquery(); 

change code this:

create method has 4 parameter pass name,address,city , state includes insert code

private void insertcustomers(string name,string address,string city,string state) {     using (sqlconnection conn = new sqlconnection(connstr))                 {                     conn.open();                     stringbuilder sqlstr = new stringbuilder("insert customers values ( @name, @address, @city, @state)");                     sqlcommand cmd = new sqlcommand(sqlstr.tostring(), conn);                     cmd.parameters.add(new sqlparameter("@name", name));                     cmd.parameters.add(new sqlparameter("@address", address));                     cmd.parameters.add(new sqlparameter("@city", city));                     cmd.parameters.add(new sqlparameter("@state", state));                     cmd.executenonquery();                  }  } 

then on click or events want insert new customer do

insertcustomers("a","b","c","d");  insertcustomers("e","f","g","h"); 

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