csvsql

Description

Generate SQL statements for a CSV file or execute those statements directly on a database. In the latter case supports both creating tables and inserting data:

usage: csvsql [-h] [-d DELIMITER] [-t] [-q QUOTECHAR] [-u {0,1,2,3}] [-b]
              [-p ESCAPECHAR] [-z FIELD_SIZE_LIMIT] [-e ENCODING] [-L LOCALE]
              [-S] [--blanks] [--date-format DATE_FORMAT]
              [--datetime-format DATETIME_FORMAT] [-H] [-K SKIP_LINES] [-v]
              [-l] [--zero] [-V]
              [-i {firebird,mssql,mysql,oracle,postgresql,sqlite,sybase}]
              [--db CONNECTION_STRING] [--query QUERY] [--insert]
              [--prefix PREFIX] [--tables TABLE_NAMES] [--no-constraints]
              [--unique-constraint UNIQUE_CONSTRAINT] [--no-create]
              [--create-if-not-exists] [--overwrite] [--db-schema DB_SCHEMA]
              [-y SNIFF_LIMIT] [-I] [--chunk-size NUM]
              [FILE [FILE ...]]

Generate SQL statements for one or more CSV files, or execute those statements
directly on a database, and execute one or more SQL queries.

positional arguments:
  FILE                  The CSV file(s) to operate on. If omitted, will accept
                        input on STDIN.

optional arguments:
  -h, --help            show this help message and exit
  -i {firebird,mssql,mysql,oracle,postgresql,sqlite,sybase}, --dialect {firebird,mssql,mysql,oracle,postgresql,sqlite,sybase}
                        Dialect of SQL to generate. Only valid when --db is
                        not specified.
  --db CONNECTION_STRING
                        If present, a sqlalchemy connection string to use to
                        directly execute generated SQL on a database.
  --query QUERY         Execute one or more SQL queries delimited by ";" and
                        output the result of the last query as CSV. QUERY may
                        be a filename.
  --insert              In addition to creating the table, also insert the
                        data into the table. Only valid when --db is
                        specified.
  --prefix PREFIX       Add an expression following the INSERT keyword, like
                        OR IGNORE or OR REPLACE.
  --tables TABLE_NAMES  A comma-separated list of names of tables to be
                        created. By default, the tables will be named after
                        the filenames without extensions or "stdin".
  --no-constraints      Generate a schema without length limits or null
                        checks. Useful when sampling big tables.
  --unique-constraint UNIQUE_CONSTRAINT
                        A column-separated list of names of columns to include
                        in a UNIQUE constraint.
  --no-create           Skip creating a table. Only valid when --insert is
                        specified.
  --create-if-not-exists
                        Create table if it does not exist, otherwise keep
                        going. Only valid when --insert is specified.
  --overwrite           Drop the table before creating. Only valid when
                        --insert is specified and --no-create is not
                        specified.
  --db-schema DB_SCHEMA
                        Optional name of database schema to create table(s)
                        in.
  -y SNIFF_LIMIT, --snifflimit SNIFF_LIMIT
                        Limit CSV dialect sniffing to the specified number of
                        bytes. Specify "0" to disable sniffing entirely.
  -I, --no-inference    Disable type inference when parsing the input.
  --chunk-size NUM
                        Chunk size for batch insert into the table.
                        Only valid when --insert is specified.

See also: Arguments common to all tools.

For information on connection strings and supported dialects refer to the SQLAlchemy documentation.

If you prefer not to enter your password in the connection string, store the password securely in a PostgreSQL Password File, a MySQL Options File or similar files for other systems.

Note

Using the --query option may cause rounding (in Python 2) or introduce [Python floating point issues](https://docs.python.org/3.4/tutorial/floatingpoint.html) (in Python 3).

Examples

Generate a statement in the PostgreSQL dialect:

csvsql -i postgresql examples/realdata/FY09_EDU_Recipients_by_State.csv

Create a table and import data from the CSV directly into PostgreSQL:

createdb test
csvsql --db postgresql:///test --tables fy09 --insert examples/realdata/FY09_EDU_Recipients_by_State.csv

For large tables it may not be practical to process the entire table. One solution to this is to analyze a sample of the table. In this case it can be useful to turn off length limits and null checks with the --no-constraints option:

head -n 20 examples/realdata/FY09_EDU_Recipients_by_State.csv | csvsql --no-constraints --tables fy09

Create tables for an entire folder of CSVs and import data from those files directly into PostgreSQL:

createdb test
csvsql --db postgresql:///test --insert examples/*_converted.csv

If those CSVs have identical headers, you can import them into the same table by using csvstack first:

createdb test
csvstack examples/dummy?.csv | csvsql --db postgresql:///test --insert

Group rows by one column:

csvsql --query "select * from 'dummy3' group by a" examples/dummy3.csv

You can also use CSVSQL to “directly” query one or more CSV files. Please note that this will create an in-memory SQL database, so it won’t be very fast:

csvsql --query  "select m.usda_id, avg(i.sepal_length) as mean_sepal_length from iris as i join irismeta as m on (i.species = m.species) group by m.species" examples/iris.csv examples/irismeta.csv

Concatenate two columns:

csvsql --query "select a||b from 'dummy3'" examples/dummy3.csv