diff --git a/Cargo.lock b/Cargo.lock
index 079887e5..5a24c011 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -232,7 +232,7 @@ dependencies = [
 
 [[package]]
 name = "gitql"
-version = "0.5.0"
+version = "0.6.0"
 dependencies = [
  "git2",
  "gitql-ast",
@@ -243,14 +243,14 @@ dependencies = [
 
 [[package]]
 name = "gitql-ast"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "lazy_static",
 ]
 
 [[package]]
 name = "gitql-cli"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "clap",
  "gitql-ast",
@@ -262,7 +262,7 @@ dependencies = [
 
 [[package]]
 name = "gitql-engine"
-version = "0.3.0"
+version = "0.4.0"
 dependencies = [
  "git2",
  "gitql-ast",
@@ -271,7 +271,7 @@ dependencies = [
 
 [[package]]
 name = "gitql-parser"
-version = "0.2.0"
+version = "0.3.0"
 dependencies = [
  "gitql-ast",
  "lazy_static",
diff --git a/Cargo.toml b/Cargo.toml
index 4623c7c9..a9eff678 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "gitql"
 authors = ["AmrDeveloper"]
-version = "0.5.0"
+version = "0.6.0"
 edition = "2021"
 description = "A SQL like query language to perform queries on .git files"
 license = "MIT"
@@ -21,8 +21,8 @@ members = [
 ]
 
 [dependencies]
-gitql-ast = { path = "./crates/gitql-ast", version = "0.1.0" }
-gitql-parser = { path = "./crates/gitql-parser", version = "0.2.0" }
-gitql-engine = { path = "./crates/gitql-engine", version = "0.3.0" }
-gitql-cli = { path = "./crates/gitql-cli", version = "0.3.0" }
+gitql-ast = { path = "./crates/gitql-ast", version = "0.2.0" }
+gitql-parser = { path = "./crates/gitql-parser", version = "0.3.0" }
+gitql-engine = { path = "./crates/gitql-engine", version = "0.4.0" }
+gitql-cli = { path = "./crates/gitql-cli", version = "0.4.0" }
 git2 = { version = "0.17.1", default-features = false }
diff --git a/README.md b/README.md
index cb9f6965..d6ff70a3 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,10 @@ GQL is a query language with a syntax very similar to SQL with a tiny engine to
 ### Samples
 
 ```sql
+SELECT 1
+SELECT 1 + 2
+SELECT LEN("Git Query Language")
+
 SELECT name, COUNT(name) AS commit_num FROM commits GROUP BY name ORDER BY commit_num DESC LIMIT 10
 SELECT commit_count FROM branches WHERE commit_count BETWEEN 0 .. 10
 
@@ -46,6 +50,7 @@ SELECT * FROM branches
 SELECT * FROM branches WHERE is_head = true
 SELECT * FROM branches WHERE name ends_with "master"
 SELECT * FROM branches WHERE name contains "origin"
+SELECT name, LEN(name) FROM branches
 
 SELECT * FROM tags
 SELECT * FROM tags OFFSET 1 LIMIT 1
diff --git a/crates/gitql-ast/Cargo.toml b/crates/gitql-ast/Cargo.toml
index 8395e3b9..cd9f4552 100644
--- a/crates/gitql-ast/Cargo.toml
+++ b/crates/gitql-ast/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "gitql-ast"
 authors = ["AmrDeveloper"]
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 description = "GitQL Abstract syntax tree (AST)"
 repository = "https://github.com/amrdeveloper/gql/tree/main/crates/gitql-ast"
diff --git a/crates/gitql-cli/Cargo.toml b/crates/gitql-cli/Cargo.toml
index e9368928..ae71dc5d 100644
--- a/crates/gitql-cli/Cargo.toml
+++ b/crates/gitql-cli/Cargo.toml
@@ -1,15 +1,15 @@
 [package]
 name = "gitql-cli"
 authors = ["AmrDeveloper"]
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 description = "GitQL Command line interface (CLI) components"
 repository = "https://github.com/amrdeveloper/gql/tree/main/crates/gitql-cli"
 license = "MIT"
 
 [dependencies]
-gitql-ast = { path = "../gitql-ast", version = "0.1.0" }
-gitql-parser = { path = "../gitql-parser", version = "0.2.0" }
+gitql-ast = { path = "../gitql-ast", version = "0.2.0" }
+gitql-parser = { path = "../gitql-parser", version = "0.3.0" }
 prettytable-rs = "^0.10"
 textwrap = "0.16.0"
 termcolor = "1.2.0"
diff --git a/crates/gitql-engine/Cargo.toml b/crates/gitql-engine/Cargo.toml
index ce8a3e60..b9af49af 100644
--- a/crates/gitql-engine/Cargo.toml
+++ b/crates/gitql-engine/Cargo.toml
@@ -1,14 +1,13 @@
 [package]
 name = "gitql-engine"
 authors = ["AmrDeveloper"]
-version = "0.3.0"
+version = "0.4.0"
 edition = "2021"
 description = "GitQL Engine"
 repository = "https://github.com/amrdeveloper/gql/tree/main/crates/gitql-engine"
 license = "MIT"
 
-
 [dependencies]
-gitql-ast = { path = "../gitql-ast", version = "0.1.0" }
+gitql-ast = { path = "../gitql-ast", version = "0.2.0" }
 git2 = { version = "0.17.1", default-features = false }
 regex = "1.8.4"
diff --git a/crates/gitql-parser/Cargo.toml b/crates/gitql-parser/Cargo.toml
index fb37e969..79e5152e 100644
--- a/crates/gitql-parser/Cargo.toml
+++ b/crates/gitql-parser/Cargo.toml
@@ -1,12 +1,12 @@
 [package]
 name = "gitql-parser"
 authors = ["AmrDeveloper"]
-version = "0.2.0"
+version = "0.3.0"
 edition = "2021"
 description = "GitQL parser"
 repository = "https://github.com/amrdeveloper/gql/tree/main/crates/gitql-parser"
 license = "MIT"
 
 [dependencies]
-gitql-ast = { path = "../gitql-ast", version = "0.1.0" }
+gitql-ast = { path = "../gitql-ast", version = "0.2.0" }
 lazy_static = "1.4.0"