extractTextSchema
Syntax
extractTextSchema(filename, [delimiter], [skipRows=0])
Arguments
filename the input data file name with its absolute path.
delimiter a STRING scalar indicating the table column separator. It can consist of one or more characters, with the default being a comma (‘,’).
skipRows is an integer between 0 and 1024 indicating the rows in the beginning of the text file to be ignored. The default value is 0.
Details
Generate the schema table for the input data file. The schema table has 2 columns: column names and their data types.
Note: From version 1.30.22 onwards, function extractTextSchema
supports a data file that contains a record with multiple newlines.
Examples
$ n=1000000
$ timestamp=09:30:00+rand(18000,n)
$ ID=rand(100,n)
$ qty=100*(1+rand(100,n))
$ price=5.0+rand(100.0,n)
$ t1 = table(timestamp,ID,qty,price)
$ saveText(t1, "C:/DolphinDB/Data/t1.txt")
$ schema=extractTextSchema("C:/DolphinDB/Data/t1.txt");
$ schema;
name |
type |
---|---|
timestamp |
SECOND |
ID |
INT |
qty |
INT |
price |
DOUBLE |