Getting LOAD DATA to Cough Up More Information
Problem
LOAD DATA
doesn’t tell you much about problems in the
datafile.
Solution
There is no solution. Well, maybe there is.
Discussion
When a LOAD DATA statement
finishes, it returns a line of information that tells you how many
errors or data conversion problems occurred. Suppose you load a file
into a table and see the following message when
LOAD DATA finishes.
Records: 134 Deleted: 0 Skipped: 2 Warnings: 13
These values provide some general information about the import operation:
Recordsindicates the number of records found in the file.DeletedandSkippedare related to treatment of input records that duplicate existing table records on unique index values.Deletedindicates how many records were deleted from the table and replaced by input records, andSkippedindicates how many input records were ignored in favor of existing records.Warningsis something of a catch-all that indicates the number of problems found while loading data values into columns. Either a value stores into a column properly, or it doesn’t. In the latter case, the value ends up in MySQL as something different and MySQL counts it as a warning. (Storing a stringabcinto a numeric column results in a stored value of0, for example.)
What do these values tell you? The Records value normally should match the number of lines in the input file. If it is different than the file’s line count, that’s a sign that MySQL is interpreting the file as having a format that ...