If statement that checks for exsisting data table

Question

Hi,

I'm trying to create a if statement that checks if a specific (table name is known) exists or not. If the table exists it should be appended to a journal. My code is as following:

//assigns the table to a variable.

Data Table( "Ber" ) << Subset( Invisible, (Selected Rows), Output Table Name( "Output" ) );

NC1 = Data Table( "Output" );

......

//Checks if the tables exists

If( try(Data Table ("Output"), TableExist = 0),

NC1 << journal

,

jrn << Append (Text Box ("Alla neg. prover har ett värde under 0.2"));

);

I've also tried with the following:

If( try(NC1, TableExist = 0),

NC1 << journal

,

jrn << Append (Text Box ("Alla neg. prover har ett värde under 0.2"));

);

Results:

Even though the table exists (no erros occurs while running the script) the table is not appended.

If the table does not exsist the text box is appended.

Why does this not work?

Kind regards

Anders

David_Burnham · Accepted Answer

This should help you:

//Checks if the tables exists

Try(

Data Table("Output");

tableExist = 1

,

tableExist = 0

);

If( tableExist,

show("exists")

,

show("doesn't exist")

);

pmroz · Accepted Answer

I use a function for this.  Once you've loaded the function, simply call it like this:

if (table_exists("Output"),

// append to journal

,

// don't append

);

Here's the function:

/*

Function Name: table_exists

Description: Returns 1 if the table exists, 0 if not

Arguments:

table_name  Table to check existence of

*/

table_exists = Function( {table_name},

{Default Local},

tbl_exists_flag = 0;

// Loop over all tables and see if this one exists

num_tables = ntable();

For (i = 1, i <= num_tables, i++,

one_name = Data Table(i) << Get Name;

if (one_name == table_name,

tbl_exists_flag = 1;

break();    // jump out of the loop now that we found the table

);

tbl_exists_flag;

);    // end table_exists function