MongoDB change or update field type

FeaturedChange / Update field type in MongoDB

Many a times developer do ask a common question that, we need to change existing data bearing field's data type to another data type with out hampering existing data. Such as example, in database date field was in string value, but need to convert it in ISODate() format. Before going to nitty gritty details of … Continue reading MongoDB change or update field type

3. Shell comparison operator & reference

CommandDescriptionExample&Run the previous command in the backgroundls &&&Logical ANDif [ "$X" -ge "0" ] && [ "$X" -le "9"]||Logical ORif [ "$X" -lt "0" ] || [ "$X" -gt "9" ]^Start of linegrep "^X"$End of linegrep "X$"=String equality (cf. -eq)if [ "$X" = "bar" ]!Logical NOTif [ "$X" != "bar" ]$$PID (Process ID)of current shellecho … Continue reading 3. Shell comparison operator & reference

1. Shell script comment variable and wildcard

As we probably all know, shell script is badly required, when you thought to automate something in your operating system. We are here using Born shell(sh) and bash in linux ubuntu. cat /etc/shells #it will give us following shells /bin/sh # Bourne Shell /bin/bash # Bourne again shell unix and windows /bin/rbash # Restricted Shell … Continue reading 1. Shell script comment variable and wildcard

MongoDB export (mongoexport) using aggregation

When we are thinking for exporting data in csv, tsv or json format from MongoDB then probably one tool we are using that is mongoexport. This is pretty straight forward and setting up all parameters will get back your desired data in desired format, but in this article we are talking about some situation which … Continue reading MongoDB export (mongoexport) using aggregation