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 MAXFIELDSIZE] [-e ENCODING] [-S] [-H] [-v]
              [--zero] [-y SNIFFLIMIT]
              [-i {firebird,maxdb,informix,mssql,oracle,sybase,sqlite,access,mysql,postgresql}]
              [--db CONNECTION_STRING] [--query QUERY] [--insert]
              [--tables TABLE_NAMES] [--no-constraints] [--no-create]
              [--blanks] [--no-inference] [--db-schema DB_SCHEMA]
              [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
  -y SNIFFLIMIT, --snifflimit SNIFFLIMIT
                        Limit CSV dialect sniffing to the specified number of
                        bytes. Specify "0" to disable sniffing entirely.
  -i {firebird,maxdb,informix,mssql,oracle,sybase,sqlite,access,mysql,postgresql}, --dialect {firebird,maxdb,informix,mssql,oracle,sybase,sqlite,access,mysql,postgresql}
                        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.
  --insert              In addition to creating the table, also insert the
                        data into the table. Only valid when --db is
                        specified.
  --tables TABLE_NAMES  Specify the names of the 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.
  --no-create           Skip creating a table. Only valid when --insert is
                        specified.
  --blanks              Do not coerce empty strings to NULL values.
  --no-inference        Disable type inference when parsing the input.
  --db-schema DB_SCHEMA
                        Optional name of database schema to create table(s)
                        in.

See also: Arguments common to all tools.

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

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 --table 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 --table 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