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MongoDB - Aggregation Operators MongoDB - Arithmetic Operators MongoDB - String Operators MongoDB - Date Operators MongoDB - Array Operators

🧵 MongoDB: String Operators

MongoDB provides powerful string operators for text manipulation, conversion, formatting, and pattern matching. These operators are mainly used within the aggregation pipeline to transform or analyze text data efficiently.

📚 Initial Data Setup — students Collection

Example01

MongoDB Shell

NoSQL

Database

1db.students.insertMany([
2  { _id: 1, name: 'Akshay Kumar', dob: 'jan 10 2010' },
3  { _id: 2, name: 'Salman Khan', dob: '2010-02-03' },
4  { _id: 3, name: 'Deepika Padukone', dob: 'june 15 2010' },
5  { _id: 4, name: 'John Abraham', dob: 'WED jan 31 12:05:28 +03:30 2010' },
6  { _id: 5, name: 'Katrina Kaif', dob: 'dec 22 2010' }
7]);

Query Result

JSON Output

✅ 5 student documents inserted successfully.

📘 Additional Data Setup — students2 Collection

Example02

MongoDB Shell

NoSQL

Database

1db.students2.insertMany([
2  { _id: 1, firstName: 'Akshay', lastName: 'Kumar', age: 25 },
3  { _id: 2, firstName: 'Salman', lastName: 'Khan', age: 23 },
4  { _id: 3, firstName: 'Deepika', lastName: 'Padukone', age: 24 },
5  { _id: 4, firstName: 'John', lastName: 'Abraham', age: 25 },
6  { _id: 5, firstName: 'Katrina', lastName: 'Kaif', age: 23 }
7]);

Query Result

JSON Output

✅ 5 student2 documents inserted successfully.

📗 Date Setup — students3 Collection

Example03

MongoDB Shell

NoSQL

Database

1db.students3.insertMany([
2  { _id: 1, name: "Akshay Kumar", dob: new ISODate("2008-01-15T08:15:39.736Z") },
3  { _id: 2, name: "Salman Khan", dob: new ISODate("2009-08-01T08:15:39.736Z") }
4]);

Query Result

JSON Output

✅ 2 student3 documents inserted successfully.

1️⃣ $toString — Convert Age to String

Example04

MongoDB Shell

NoSQL

Database

1db.students2.aggregate([
2  { $project: { age: 1, ageString: { $toString: "$age" } } }
3]);

Query Result

JSON Output

{ age: 25, ageString: "25" }

2️⃣ $toUpper — Convert to Uppercase

Example05

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, upperName: { $toUpper: "$name" } } }
3]);

Query Result

JSON Output

{ name: "Akshay Kumar", upperName: "AKSHAY KUMAR" }

3️⃣ $toLower — Convert to Lowercase

Example06

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, lowerName: { $toLower: "$name" } } }
3]);

Query Result

JSON Output

{ name: "Salman Khan", lowerName: "salman khan" }

4️⃣ $strLenBytes — Byte Length of String

Example07

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, length: { $strLenBytes: "$name" } } }
3]);

Query Result

JSON Output

{ name: "Deepika Padukone", length: 16 }

5️⃣ $strLenCP — Code Point Length

Example08

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, length: { $strLenCP: "$name" } } }
3]);

Query Result

JSON Output

{ name: "John Abraham", length: 12 }

6️⃣ $strcasecmp — Case-Insensitive Comparison

Example09

MongoDB Shell

NoSQL

Database

1db.students2.aggregate([
2  { $project: { name: 1, match: { $strcasecmp: ["$firstName", "akshay"] } } }
3]);

Query Result

JSON Output

{ name: "Akshay Kumar", match: 0 } // 0 means match

7️⃣ $substr — Deprecated Substring

Example10

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, first3: { $substr: ["$name", 0, 3] } } }
3]);

Query Result

JSON Output

{ name: "Katrina Kaif", first3: "Kat" }

8️⃣ $substrBytes — Byte-Based Substring

Example11

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, last5: { $substrBytes: ["$name", -5, 5] } } }
3]);

Query Result

JSON Output

{ name: "Salman Khan", last5: "Khan" }

9️⃣ $substrCP — Code Point Substring

Example12

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, lastName: { 
3    $substrCP: ["$name", { $add: [ { $indexOfCP: ["$name", " "] }, 1 ] }, 100] 
4  } } }
5]);

Query Result

JSON Output

{ name: "Akshay Kumar", lastName: "Kumar" }

🔟 $replaceOne — Replace First Match

Example13

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, modified: { $replaceOne: { input: "$name", find: "a", replacement: "@" } } } }
3]);

Query Result

JSON Output

{ name: "Katrina Kaif", modified: "K@trina Kaif" }

1️⃣1️⃣ $replaceAll — Replace All Matches

Example14

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, modified: { $replaceAll: { input: "$name", find: "a", replacement: "@" } } } }
3]);

Query Result

JSON Output

{ name: "Katrina Kaif", modified: "K@trin@ K@if" }

1️⃣2️⃣ $concat — Combine Strings

Example15

MongoDB Shell

NoSQL

Database

1db.students2.aggregate([
2  { $project: { fullName: { $concat: ["$firstName", " ", "$lastName"] } } }
3]);

Query Result

JSON Output

{ fullName: "John Abraham" }

1️⃣3️⃣ $split — Split String into Array

Example16

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, parts: { $split: ["$name", " "] } } }
3]);

Query Result

JSON Output

{ name: "Deepika Padukone", parts: ["Deepika", "Padukone"] }

1️⃣4️⃣ $ltrim — Left Trim

Example17

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, clean: { $ltrim: { input: { $concat: ["   ", "$name"] } } } } }
3]);

Query Result

JSON Output

{ name: "Salman Khan", clean: "Salman Khan" }

1️⃣5️⃣ $rtrim — Right Trim

Example18

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, clean: { $rtrim: { input: { $concat: ["$name", "   "] } } } } }
3]);

Query Result

JSON Output

{ name: "Akshay Kumar", clean: "Akshay Kumar" }

1️⃣6️⃣ $trim — Trim Both Sides

Example19

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, clean: { $trim: { input: { $concat: ["   ", "$name", "   "] } } } } }
3]);

Query Result

JSON Output

{ name: "John Abraham", clean: "John Abraham" }

1️⃣7️⃣ $dateFromString — Convert String to Date

Example20

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, dobDate: { $dateFromString: { dateString: "$dob"} } } }
3]);

Query Result

JSON Output

{ name: "Akshay Kumar", dobDate: ISODate("2010-01-10T00:00:00Z") }

1️⃣8️⃣ $dateToString — Convert Date to String

Example21

MongoDB Shell

NoSQL

Database

1db.students3.aggregate([
2  { $project: { name: 1, dobStr: { $dateToString: { format: "%Y-%m-%d", date: "$dob" } } } }
3]);

Query Result

JSON Output

{ name: "Salman Khan", dobStr: "2009-08-01" }

1️⃣9️⃣ $indexOfBytes — Find Byte Position

Example22

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, pos: { $indexOfBytes: ["$name", "K"] } } }
3]);

Query Result

JSON Output

{ name: "Akshay Kumar", pos: 7 }

2️⃣0️⃣ $indexOfCP — Find Code Point Position

Example23

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, pos: { $indexOfCP: ["$name", "K"] } } }
3]);

Query Result

JSON Output

{ name: "Katrina Kaif", pos: 0 }

2️⃣1️⃣ $regexFind — Find First Regex Match

Example24

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, match: { $regexFind: { input: "$name", regex: "K.*n" } } } }
3]);

Query Result

JSON Output

{ name: "Salman Khan", match: { match: "Khan", idx: 7, captures: [] } }

2️⃣2️⃣ $regexFindAll — Find All Regex Matches

Example25

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, matches: { $regexFindAll: { input: "$name", regex: "a" } } } }
3]);

Query Result

JSON Output

{ name: "Katrina Kaif", matches: [{ match: "a", idx: 1 }, { match: "a", idx: 6 }, { match: "a", idx: 9 }] }

2️⃣3️⃣ $regexMatch — Regex Test

Example26

MongoDB Shell

NoSQL

Database

1db.students.aggregate([
2  { $project: { name: 1, hasK: { $regexMatch: { input: "$name", regex: "K" } } } }
3]);

Query Result

JSON Output

{ name: "Akshay Kumar", hasK: true }

MongoDB

Nearby lessons

🧵 MongoDB: String Operators

01📚 Initial Data Setup — students Collection

02📘 Additional Data Setup — students2 Collection

03📗 Date Setup — students3 Collection

041️⃣ $toString — Convert Age to String

052️⃣ $toUpper — Convert to Uppercase

063️⃣ $toLower — Convert to Lowercase

074️⃣ $strLenBytes — Byte Length of String

085️⃣ $strLenCP — Code Point Length

096️⃣ $strcasecmp — Case-Insensitive Comparison

107️⃣ $substr — Deprecated Substring

118️⃣ $substrBytes — Byte-Based Substring

129️⃣ $substrCP — Code Point Substring

13🔟 $replaceOne — Replace First Match

141️⃣1️⃣ $replaceAll — Replace All Matches

151️⃣2️⃣ $concat — Combine Strings

161️⃣3️⃣ $split — Split String into Array

171️⃣4️⃣ $ltrim — Left Trim

181️⃣5️⃣ $rtrim — Right Trim

191️⃣6️⃣ $trim — Trim Both Sides

201️⃣7️⃣ $dateFromString — Convert String to Date

211️⃣8️⃣ $dateToString — Convert Date to String

221️⃣9️⃣ $indexOfBytes — Find Byte Position

232️⃣0️⃣ $indexOfCP — Find Code Point Position

242️⃣1️⃣ $regexFind — Find First Regex Match

252️⃣2️⃣ $regexFindAll — Find All Regex Matches

262️⃣3️⃣ $regexMatch — Regex Test

📚 Initial Data Setup — students Collection

📘 Additional Data Setup — students2 Collection

📗 Date Setup — students3 Collection

1️⃣ $toString — Convert Age to String

2️⃣ $toUpper — Convert to Uppercase

3️⃣ $toLower — Convert to Lowercase

4️⃣ $strLenBytes — Byte Length of String

5️⃣ $strLenCP — Code Point Length

6️⃣ $strcasecmp — Case-Insensitive Comparison

7️⃣ $substr — Deprecated Substring

8️⃣ $substrBytes — Byte-Based Substring

9️⃣ $substrCP — Code Point Substring

🔟 $replaceOne — Replace First Match

1️⃣1️⃣ $replaceAll — Replace All Matches

1️⃣2️⃣ $concat — Combine Strings

1️⃣3️⃣ $split — Split String into Array

1️⃣4️⃣ $ltrim — Left Trim

1️⃣5️⃣ $rtrim — Right Trim

1️⃣6️⃣ $trim — Trim Both Sides

1️⃣7️⃣ $dateFromString — Convert String to Date

1️⃣8️⃣ $dateToString — Convert Date to String

1️⃣9️⃣ $indexOfBytes — Find Byte Position

2️⃣0️⃣ $indexOfCP — Find Code Point Position

2️⃣1️⃣ $regexFind — Find First Regex Match

2️⃣2️⃣ $regexFindAll — Find All Regex Matches

2️⃣3️⃣ $regexMatch — Regex Test