Learning SQL statements-select (1): specifying a table

// Select * from country {all fields in the country table are case-insensitive, but the keywords should be capitalized}

  
 

In this example:

Code File:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls, extctrls, grids, dbgrids, DB, ADODB; type tform1 = Class (tform) Panel1: tpanel; button1: tbutton; button2: tbutton; dbgrid1: TDBGrid; performance1: tdatasource; adodataset1: dependencies; Procedure dependencies (Sender: tobject ); procedure button1click (Sender: tobject); Procedure button2click (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} {view database dbdemos. country table in MDB} procedure tform1.button1click (Sender: tobject); begin adodataset1.close; adodataset1.commandtext: = 'select * from country '; adodataset1.open; end; {view database dbdemos. in mdb, the customer table} procedure tform1.button2click (Sender: tobject); begin with adodataset1 do begin close; commandtext: = 'select * From customer'; open; end; {Control Association and database connection: dbdemos. MDB} procedure tform1.formcreate (Sender: tobject); var mdbfile: string; begin {obtain the data file of codegear shared installation: dbdemos. MDB path} mdbfile: = getenvironmentvariable ('commonprogramfiles'); {C: \ Program Files \ common files} mdbfile: = mdbfile + '\ codegear shared \ data \ dbdemos. MDB '; adodataset1.connectionstring: = 'provider = Microsoft. jet. oledb.4.0; Data Source = '+ mdbfile +'; persist Security info = false'; dbgrid1.datasource: = performance1; performance1.dataset: = adodataset1; end.
 
   
 

Form file:

Object form1: tform1 left = 0 Top = 0 caption = 'form1' clientheight = 407 clientwidth = 645 color = clbtnface font. charset = default_charset font. color = clwindowtext font. height =-11 font. name = 'tahoma 'font. style = [] oldcreateorder = false oncreate = formcreate pixelsperinch = 96 textheight = 13 object dbgrid1: TDBGrid left = 0 Top = 35 width = 645 Height = 372 align = alclient datasource = performance1 taborder = 0 titlefont. charset = default_charset titlefont. color = clwindowtext titlefont. height =-11 titlefont. name = 'tahoma 'titlefont. style = [] end object Panel1: tpanel left = 0 Top = 0 width = 645 Height = 35 align = altop caption = 'panel1' taborder = 1 object button1: tbutton left = 16 Top = 4 width = 75 Height = 25 caption = 'button1' taborder = 0 onclick = button1click end object button2: tbutton left = 97 top = 4 width = 75 Height = 25 caption = 'button2' taborder = 1 onclick = button2click end object performance1: tdatasource dataset = adodataset1 left = 184 Top = 112 end object adodataset1: TADODataSet cursortype = ctstatic parameters = left = 232 Top = 184 endend