Hello,   I'm interested in creating a do loop while a macro variable shows there is a error grater than 0. I'm setting the macro variable as the result of a proc sql query. here what my code look like:     %Macro MacroSample(RL=) %let TableName1 = "1&RL. Table1Name"n; %let TableName2 = "2&RL. Table2Name"n; PROC SQL; CREATE TABLE WORK.&tablename2. AS SELECT (SUM(t1.'Connection Difference'n)) AS 'Connection Difference'n  Into : CheckFlag FROM WORK.&tablename1. t1; Where t1.Field1 = &RL.; %Let CheckFlag = &CheckFlag;   QUIT; /* Macro Begins if Connection Mismaches Fails */ %Do %while (&CheckFlag. >0);   /* Begin loop by updating the original table until sum of error is 0*/ PROC SQL; CREATE TABLE WORK.&tablename1. AS SELECT Libref1.Field1, Libref1.Field2 Calculation1 AS 'Connection Difference'n FROM WORK.&TableName1. t1;  QUIT; 　CREATE TABLE WORK.&tablename2. AS SELECT (SUM(t1.'Connection Difference'n)) AS 'Connection Difference'n  Into : CheckFlag FROM WORK.&tablename1. t1; %Let CheckFlag = &CheckFlag;   %End %Mend MacroSample; %MacroSample(RL= "Low") ... View more