convert multiple DBs to CSV - batch-file

Question

I have thousands of dB files that need to be converted to CSV files. This can be achieved by a simple script / batch file i.e.
.open "Test.db"
.mode csv
.headers on.
I need the script to open the other db files which all have different names, is there a way that this can be performed as i do not want to write the above script for each db file

Answer 1

I made a script that batch-converts all db-sqlite files in the current directory to CSV, called 'sqlite2csv'. Well it outputs each table of each db-sqlite as a CSV file, so if you have 10 files with 3 tables each you will get 30 CSV files. Hope it helps at least as a starting point to make your own script.
#!/bin/bash
# USAGE EXAMPLES :
# sqlite2csv
# - Will loop all sqlite files in the current directory, take the tables of
# each of these sqlite files, and generate a CSV file per table.
# E.g. If there are 10 sqlite files with 3 tables each, it will generate
# 30 CSV output files, each containing the data of one table.
# The naming of the generated CSV files take from the original sqlite
# file name, prepended with the name of the table.
# check for dependencies
if ! type "sqlite3" > /dev/null; then
echo "[ERROR] SQLite binary not found."
exit 1
fi
# define list of string tokens that an SQLite file type should contain
# the footprint for SQLite 3 is "SQLite 3.x database"
declare -a list_sqlite_tok
list_sqlite_tok+=( "SQLite" )
#list_sqlite_tok+=( "3.x" )
list_sqlite_tok+=( "database" )
# get a lis tof only files in current path
list_files=( $(find . -maxdepth 1 -type f) )
# loop the list of files
for f in ${!list_files[#]}; do
# get current file
curr_fname=${list_files[$f]}
# get file type result
curr_ftype=$(file -e apptype -e ascii -e encoding -e tokens -e cdf -e compress -e elf -e tar $curr_fname)
# loop through necessary token and if one is not found then skip this file
curr_isqlite=0
for t in ${!list_sqlite_tok[#]}; do
curr_tok=${list_sqlite_tok[$t]}
# check if 'curr_ftype' contains 'curr_tok'
if [[ $curr_ftype =~ $curr_tok ]]; then
curr_isqlite=1
else
curr_isqlite=0
break
fi
done
# test if curr file was sqlite
if (( ! $curr_isqlite )); then
# if not, do not continue executung rest of script
continue
fi
# print sqlite filename
echo "[INFO] Found SQLite file $curr_fname, exporting tables..."
# get tables of sqlite file in one line
curr_tables=$(sqlite3 $curr_fname ".tables")
# split tables line into an array
IFS=$' ' list_tables=($curr_tables)
# loop array to export each table
for t in ${!list_tables[#]}; do
curr_table=${list_tables[$t]}
# strip unsafe characters as well as newline
curr_table=$(tr '\n' ' ' <<< $curr_table)
curr_table=$(sed -e 's/[^A-Za-z0-9._-]//g' <<< $curr_table)
# temporarily strip './' from filename
curr_fname=${curr_fname//.\//}
# build target CSV filename
printf -v curr_csvfname "%s_%s.csv" $curr_table "$curr_fname"
# put back './' to filenames
curr_fname="./"$curr_fname
curr_csvfname="./"$curr_csvfname
# export current table to target CSV file
sqlite3 -header -csv $curr_fname "select * from $curr_table;" > $curr_csvfname
# log
echo "[INFO] Exported table $curr_table in file $curr_csvfname"
done
done

Answer 2

The sqlite3 command-line shell allows some settings to be done with command-line arguments, so you can simply execute a simple SELECT * for the table in each DB file:
for %%a in (*.db) do sqlite3 -csv -header "%%a" "select * from TableName" > %%~na.csv
(When this is not part of a batch file but run directly from the command line, you must replace %% with %.)

Answer 3

I prepared a short python script which will write a csv file from multiple sqlite databases.
#function for merging sqlite files to csv
def convert_sqlite_to_csv(inputFolder, ext, tableName):
""" inputFolder - Folder where sqlite files are located.
ext - Extension of your sqlite file (eg. db, sqlite, sqlite3 etc.)
tableName - table name from which you want to select the data.
"""
csvWriter = csv.writer(open(inputFolder+'/output.csv', 'w', newline=''))
for file1 in os.listdir(inputFolder):
if file1.endswith('.'+ext):
conn = sqlite3.connect(inputFolder+'/'+file1)
cursor = conn.cursor()
cursor.execute("SELECT * FROM "+tableName)
rows = cursor.fetchall()
for row in rows:
csvWriter.writerow(row)
continue
else:
continue
Or find the script on github link below for converting multiple files in a folder.
python multiple_sqlite_files_tocsv.py -d <inputFolder> -e <extension> -t <tableName>
will output the data to output.csv file.
Jupyter notebook and a python script are on github.
https://github.com/darshanz/CombineMultipleSqliteToCsv