setColumnComment

setColumnComment(table, columnComments)

table is a DFS table or MVCC table.

columnComments is a dictionary. Its keys are table columns and values are comments for each column.

Add comments to columns of a DFS table or an MVCC table. Use function schema to view column comments.

n=1000000
sym=rand(`A`B`C`D`E`F,n)
date=rand(2019.06.01..2019.06.10,n)
open=rand(100.0,n)
high=rand(200.0,n)
close=rand(200.0,n)
pre_close=rand(200.0,n)
change=rand(100.0,n)
vol=rand(10000,n)
amount=rand(100000.0,n)
t=table(sym,date,open,high,close,pre_close,change,vol,amount);

db1=database("",VALUE,2019.06.01..2019.06.10)
db2=database("",VALUE,`A`B`C`D`E`F)
db=database("dfs://db1",COMPO,[db1,db2])
pt=db.createPartitionedTable(t,`pt,`date`sym).append!(t);

setColumnComment(pt,{sym:"stock ticker", date:"trading date", open:"open price", high:"highest price", low:"lowest price", close:"close price", vol:"trading volume (shares)", amount:"trading volume (dollar)"})
schema(pt).colDefs;

id=`XOM`GS`AAPL
x=102.1 33.4 73.6
mt = mvccTable(id, x);
setColumnComment(mt, {id:"identifier"})
schema(mt).colDefs