init research
This commit is contained in:
@@ -0,0 +1,234 @@
|
||||
[//]: # (title: Gradle Plugin (deprecated))
|
||||
|
||||
> The current Gradle plugin is **under consideration for deprecation** and may be officially marked as deprecated in future releases.
|
||||
>
|
||||
> At the moment, **[data schema generation is handled via dedicated methods](DataSchemaGenerationMethods.md)** instead of relying on the plugin.
|
||||
{style="warning"}
|
||||
|
||||
This page describes the Gradle plugin that generates `@DataSchema` from data samples.
|
||||
```Kotlin
|
||||
id("org.jetbrains.kotlinx.dataframe") version "%dataFrameVersion%"
|
||||
```
|
||||
|
||||
It's different from the DataFrame compiler plugin:
|
||||
```kotlin
|
||||
kotlin("plugin.dataframe") version "%compilerPluginKotlinVersion%"
|
||||
```
|
||||
|
||||
Gradle plugin by default adds a KSP annotation processor to your build:
|
||||
|
||||
```kotlin
|
||||
ksp("org.jetbrains.kotlinx.dataframe:symbol-processor-all:%dataFrameVersion%")
|
||||
```
|
||||
|
||||
You should disable it if you want to use the Gradle plugin together with the compiler plugin.
|
||||
|
||||
Add this to `gradle.properties`:
|
||||
```properties
|
||||
kotlin.dataframe.add.ksp=false
|
||||
```
|
||||
|
||||
## Examples
|
||||
In the best scenario, your schema could be defined as simple as this:
|
||||
```kotlin
|
||||
dataframes {
|
||||
// output: build/generated/dataframe/main/kotlin/org/example/dataframe/JetbrainsRepositories.Generated.kt
|
||||
schema {
|
||||
data = "https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv"
|
||||
}
|
||||
}
|
||||
```
|
||||
Note that the name of the file and the interface are normalized: split by '_' and ' ' and joined to CamelCase.
|
||||
You can set parsing options for CSV:
|
||||
```kotlin
|
||||
dataframes {
|
||||
// output: build/generated/dataframe/main/kotlin/org/example/dataframe/JetbrainsRepositories.Generated.kt
|
||||
schema {
|
||||
data = "https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv"
|
||||
csvOptions {
|
||||
delimiter = ','
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
In this case, the output path will depend on your directory structure.
|
||||
For project with package `org.example` path will be `build/generated/dataframe/main/kotlin/org/example/dataframe/JetbrainsRepositories.Generated.kt
|
||||
`.
|
||||
|
||||
Note that the name of the Kotlin file is derived from the name of the data file with the suffix
|
||||
`.Generated` and the package
|
||||
is derived from the directory structure with child directory `dataframe`.
|
||||
|
||||
The name of the **data schema** itself is `JetbrainsRepositories`.
|
||||
You could specify it explicitly:
|
||||
|
||||
```kotlin
|
||||
schema {
|
||||
// output: build/generated/dataframe/main/kotlin/org/example/dataframe/MyName.Generated.kt
|
||||
data = "https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv"
|
||||
name = "MyName"
|
||||
}
|
||||
```
|
||||
|
||||
If you want to change the default package for all schemas:
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
packageName = "org.example"
|
||||
// Schemas...
|
||||
}
|
||||
```
|
||||
|
||||
Then you can set packageName for specific schema exclusively:
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
// output: build/generated/dataframe/main/kotlin/org/example/data/OtherName.Generated.kt
|
||||
schema {
|
||||
packageName = "org.example.data"
|
||||
data = file("path/to/data.csv")
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
If you want non-default name and package, consider using fully qualified name:
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
// output: build/generated/dataframe/main/kotlin/org/example/data/OtherName.Generated.kt
|
||||
schema {
|
||||
name = "org.example.data.OtherName"
|
||||
data = file("path/to/data.csv")
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
By default, the plugin will generate output in a specified source set.
|
||||
Source set could be specified for all schemas or for specific schema:
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
packageName = "org.example"
|
||||
sourceSet = "test"
|
||||
// output: build/generated/dataframe/test/kotlin/org/example/Data.Generated.kt
|
||||
schema {
|
||||
data = file("path/to/data.csv")
|
||||
}
|
||||
// output: build/generated/dataframe/integrationTest/kotlin/org/example/Data.Generated.kt
|
||||
schema {
|
||||
sourceSet = "integrationTest"
|
||||
data = file("path/to/data.csv")
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
If you need the generated files to be put in another directory, set `src`:
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
// output: schemas/org/example/test/OtherName.Generated.kt
|
||||
schema {
|
||||
data = "https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv"
|
||||
name = "org.example.test.OtherName"
|
||||
src = file("schemas")
|
||||
}
|
||||
}
|
||||
```
|
||||
## Schema Definitions from SQL Databases
|
||||
|
||||
To generate a schema for an existing SQL table,
|
||||
you need to define a few parameters to establish a JDBC connection:
|
||||
URL (passing to `data` field), username, and password.
|
||||
|
||||
Also, the `tableName` parameter should be specified to convert the data from the table with that name to the dataframe.
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
schema {
|
||||
data = "jdbc:mariadb://localhost:3306/imdb"
|
||||
name = "org.example.imdb.Actors"
|
||||
jdbcOptions {
|
||||
user = "root"
|
||||
password = "pass"
|
||||
tableName = "actors"
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
To generate a schema for the result of an SQL query,
|
||||
you need to define the same parameters as before together with the SQL query to establish connection.
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
schema {
|
||||
data = "jdbc:mariadb://localhost:3306/imdb"
|
||||
name = "org.example.imdb.TarantinoFilms"
|
||||
jdbcOptions {
|
||||
user = "root"
|
||||
password = "pass"
|
||||
sqlQuery = """
|
||||
SELECT name, year, rank,
|
||||
GROUP_CONCAT (genre) as "genres"
|
||||
FROM movies JOIN movies_directors ON movie_id = movies.id
|
||||
JOIN directors ON directors.id=director_id LEFT JOIN movies_genres ON movies.id = movies_genres.movie_id
|
||||
WHERE directors.first_name = "Quentin" AND directors.last_name = "Tarantino"
|
||||
GROUP BY name, year, rank
|
||||
ORDER BY year
|
||||
"""
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Find full example code [here](https://github.com/zaleslaw/KotlinDataFrame-SQL-Examples/blob/master/src/main/kotlin/Example_3_Import_schema_via_Gradle.kt).
|
||||
|
||||
**NOTE:** This is an experimental functionality and, for now,
|
||||
we only support these databases: MariaDB, MySQL, PostgreSQL, SQLite, MS SQL, and DuckDB.
|
||||
|
||||
Additionally, support for JSON and date-time types is limited.
|
||||
Please take this into consideration when using these functions.
|
||||
|
||||
## DSL reference
|
||||
Inside `dataframes` you can configure parameters that will apply to all schemas.
|
||||
Configuration inside `schema` will override these defaults for a specific schema.
|
||||
Here is the full DSL for declaring data schemas:
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
sourceSet = "mySources" // [optional; default: "main"]
|
||||
packageName = "org.jetbrains.data" // [optional; default: common package under source set]
|
||||
|
||||
visibility = // [optional; default: if explicitApiMode enabled then EXPLICIT_PUBLIC, else IMPLICIT_PUBLIC]
|
||||
// KOTLIN SCRIPT: DataSchemaVisibility.INTERNAL DataSchemaVisibility.IMPLICIT_PUBLIC, DataSchemaVisibility.EXPLICIT_PUBLIC
|
||||
// GROOVY SCRIPT: 'internal', 'implicit_public', 'explicit_public'
|
||||
|
||||
withoutDefaultPath() // disable a default path for all schemas
|
||||
// i.e., plugin won't copy "data" property of the schemas to generated companion objects
|
||||
|
||||
// split property names by delimiters (arguments of this method), lowercase parts and join to camel case
|
||||
// enabled by default
|
||||
withNormalizationBy('_') // [optional: default: ['\t', '_', ' ']]
|
||||
withoutNormalization() // disable property names normalization
|
||||
|
||||
schema {
|
||||
sourceSet /* String */ = "…" // [optional; override default]
|
||||
packageName /* String */ = "…" // [optional; override default]
|
||||
visibility /* DataSchemaVisibility */ = "…" // [optional; override default]
|
||||
src /* File */ = file("…") // [optional; default: file("build/generated/dataframe/$sourceSet/kotlin")]
|
||||
|
||||
data /* URL | File | String */ = "…" // Data in JSON or CSV formats
|
||||
name = "org.jetbrains.data.Person" // [optional; default: from filename]
|
||||
csvOptions {
|
||||
delimiter /* Char */ = ';' // [optional; default: ',']
|
||||
}
|
||||
|
||||
// See names normalization
|
||||
withNormalizationBy('_') // enable property names normalization for this schema and use these delimiters
|
||||
withoutNormalization() // disable property names normalization for this schema
|
||||
|
||||
withoutDefaultPath() // disable the default path for this schema
|
||||
withDefaultPath() // enable the default path for this schema
|
||||
}
|
||||
}
|
||||
```
|
||||
@@ -0,0 +1,157 @@
|
||||
[//]: # (title: Data Schemas in Gradle projects)
|
||||
|
||||
<!---IMPORT org.jetbrains.kotlinx.dataframe.samples.api.Schemas-->
|
||||
|
||||
> The current Gradle plugin is **under consideration for deprecation** and may be officially marked as deprecated in future releases.
|
||||
>
|
||||
> At the moment, **[data schema generation is handled via dedicated methods](DataSchemaGenerationMethods.md)** instead of relying on the plugin.
|
||||
{style="warning"}
|
||||
|
||||
In Gradle projects, the Kotlin DataFrame library provides
|
||||
|
||||
1. Annotation processing for generation of extension properties
|
||||
2. Annotation processing for [`DataSchema`](schemas.md) inference from datasets.
|
||||
3. Gradle task for [`DataSchema`](schemas.md) inference from datasets.
|
||||
|
||||
### Configuration
|
||||
|
||||
To use the [extension properties API](extensionPropertiesApi.md) in Gradle project add the `dataframe` plugin as follows:
|
||||
|
||||
<tabs>
|
||||
<tab title="Kotlin DSL">
|
||||
|
||||
```kotlin
|
||||
plugins {
|
||||
id("org.jetbrains.kotlinx.dataframe") version "%dataFrameVersion%"
|
||||
}
|
||||
|
||||
dependencies {
|
||||
implementation("org.jetbrains.kotlinx:dataframe:%dataFrameVersion%")
|
||||
}
|
||||
```
|
||||
|
||||
</tab>
|
||||
|
||||
<tab title="Groovy DSL">
|
||||
|
||||
```groovy
|
||||
plugins {
|
||||
id("org.jetbrains.kotlinx.dataframe") version "%dataFrameVersion%"
|
||||
}
|
||||
|
||||
dependencies {
|
||||
implementation 'org.jetbrains.kotlinx:dataframe:%dataFrameVersion%'
|
||||
}
|
||||
```
|
||||
|
||||
</tab>
|
||||
|
||||
</tabs>
|
||||
|
||||
### Annotation processing
|
||||
|
||||
Declare data schemas in your code and use them to access data in [`DataFrame`](DataFrame.md) objects.
|
||||
A data schema is a class or interface annotated with [`@DataSchema`](schemas.md):
|
||||
|
||||
```kotlin
|
||||
import org.jetbrains.kotlinx.dataframe.annotations.DataSchema
|
||||
|
||||
@DataSchema
|
||||
interface Person {
|
||||
val name: String
|
||||
val age: Int
|
||||
}
|
||||
```
|
||||
|
||||
#### Execute the `assemble` task to generate type-safe accessors for schemas:
|
||||
|
||||
<!---FUN useProperties-->
|
||||
|
||||
```kotlin
|
||||
val df = dataFrameOf("name", "age")(
|
||||
"Alice", 15,
|
||||
"Bob", 20,
|
||||
).cast<Person>()
|
||||
// age only available after executing `build` or `kspKotlin`!
|
||||
val teens = df.filter { age in 10..19 }
|
||||
teens.print()
|
||||
```
|
||||
|
||||
<!---END-->
|
||||
|
||||
### Schema inference
|
||||
|
||||
Specify schema with preferred method and execute the `assemble` task.
|
||||
|
||||
<tabs>
|
||||
<tab title="Method 1. Annotation processing">
|
||||
|
||||
`@ImportDataSchema` annotation must be above package directive.
|
||||
You can import schemas from a URL or from the relative path of a file.
|
||||
Relative path by default is resolved to the project root directory.
|
||||
You can configure it by [passing](https://kotlinlang.org/docs/ksp-quickstart.html#pass-options-to-processors) `dataframe.resolutionDir`
|
||||
option to preprocessor.
|
||||
For example:
|
||||
|
||||
```kotlin
|
||||
ksp {
|
||||
arg("dataframe.resolutionDir", file("data").absolutePath)
|
||||
}
|
||||
```
|
||||
|
||||
**Note that due to incremental processing, imported schema will be re-generated only if some source code has changed
|
||||
from the previous invocation, at least one character.**
|
||||
|
||||
For the following configuration, file `Repository.Generated.kt` will be generated to `build/generated/ksp/` folder in
|
||||
the same package as file containing the annotation.
|
||||
|
||||
```kotlin
|
||||
@file:ImportDataSchema(
|
||||
"Repository",
|
||||
"https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv",
|
||||
)
|
||||
|
||||
import org.jetbrains.kotlinx.dataframe.annotations.ImportDataSchema
|
||||
import org.jetbrains.kotlinx.dataframe.api.*
|
||||
```
|
||||
|
||||
See KDocs for `@ImportDataSchema` in IDE
|
||||
or [GitHub](https://github.com/Kotlin/dataframe/blob/master/core/src/main/kotlin/org/jetbrains/kotlinx/dataframe/annotations/ImportDataSchema.kt)
|
||||
for more details.
|
||||
|
||||
</tab>
|
||||
|
||||
<tab title="Method 2. Gradle task">
|
||||
|
||||
Put this in `build.gradle` or `build.gradle.kts`
|
||||
For the following configuration, file `Repository.Generated.kt` will be generated
|
||||
to `build/generated/dataframe/org/example` folder.
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
schema {
|
||||
data = "https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv"
|
||||
name = "org.example.Repository"
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
See [reference](Gradle-Plugin.md) and [examples](Gradle-Plugin.md#examples) for more details.
|
||||
|
||||
</tab>
|
||||
</tabs>
|
||||
|
||||
After `assemble`, the following code should compile and run:
|
||||
|
||||
<!---FUN useInferredSchema-->
|
||||
|
||||
```kotlin
|
||||
// Repository.readCsv() has argument 'path' with default value https://raw.githubusercontent.com/Kotlin/dataframe/master/data/jetbrains_repositories.csv
|
||||
val df = Repository.readCsv()
|
||||
// Use generated properties to access data in rows
|
||||
df.maxBy { stargazersCount }.print()
|
||||
// Or to access columns in dataframe.
|
||||
print(df.fullName.count { it.contains("kotlin") })
|
||||
```
|
||||
|
||||
<!---END-->
|
||||
+75
@@ -0,0 +1,75 @@
|
||||
[//]: # (title: Import OpenAPI Schemas in Gradle project (Experimental))
|
||||
|
||||
<!---IMPORT org.jetbrains.kotlinx.dataframe.samples.api.Schemas-->
|
||||
|
||||
> The current Gradle plugin is **under consideration for deprecation** and may be officially marked as deprecated in future releases.
|
||||
>
|
||||
> At the moment, **[data schema generation is handled via dedicated methods](DataSchemaGenerationMethods.md)** instead of relying on the plugin.
|
||||
{style="warning"}
|
||||
|
||||
<warning>
|
||||
OpenAPI 3.0.0 schema support is marked as experimental. It might change or be removed in the future.
|
||||
</warning>
|
||||
|
||||
JSON schema inference is great, but it's not perfect. However, more and more APIs offer
|
||||
[OpenAPI (Swagger)](https://swagger.io/) specifications.
|
||||
|
||||
Aside from API endpoints, they also hold
|
||||
[Data Models](https://swagger.io/docs/specification/data-models/) which include all the information about the types
|
||||
that can be returned from or supplied to the API.
|
||||
|
||||
Why should we reinvent the wheel and write our own schema inference
|
||||
when we can use the one provided by the API?
|
||||
|
||||
Not only will we now get the proper names of the types, but we will also
|
||||
get enums, correct inheritance and overall better type safety.
|
||||
|
||||
First of all, you will need the extra dependency:
|
||||
|
||||
```kotlin
|
||||
implementation("org.jetbrains.kotlinx:dataframe-openapi:$dataframe_version")
|
||||
```
|
||||
|
||||
OpenAPI type schemas can be generated using both methods described above:
|
||||
|
||||
```kotlin
|
||||
@file:ImportDataSchema(
|
||||
path = "https://petstore3.swagger.io/api/v3/openapi.json",
|
||||
name = "PetStore",
|
||||
enableExperimentalOpenApi = true,
|
||||
)
|
||||
|
||||
import org.jetbrains.kotlinx.dataframe.annotations.ImportDataSchema
|
||||
```
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
schema {
|
||||
data = "https://petstore3.swagger.io/api/v3/openapi.json"
|
||||
name = "PetStore"
|
||||
}
|
||||
enableExperimentalOpenApi = true
|
||||
}
|
||||
```
|
||||
|
||||
The only difference is that the name provided is now irrelevant, since the type names are provided by the OpenAPI spec.
|
||||
(If you were wondering, yes, the Kotlin DataFrame library can tell the difference between an OpenAPI spec and normal JSON data)
|
||||
|
||||
After importing the data schema, you can now start to import any JSON data you like using the generated schemas.
|
||||
For instance, one of the types in the schema above is `PetStore.Pet` (which can also be
|
||||
explored [here](https://petstore3.swagger.io/)),
|
||||
so let's parse some Pets:
|
||||
|
||||
```kotlin
|
||||
val df: DataFrame<PetStore.Pet> =
|
||||
PetStore.Pet.readJson("https://petstore3.swagger.io/api/v3/pet/findByStatus?status=available")
|
||||
```
|
||||
|
||||
Now you will have a correctly typed [`DataFrame`](DataFrame.md)!
|
||||
|
||||
You can also always ctrl+click on the `PetStore.Pet` type to see all the generated schemas.
|
||||
|
||||
If you experience any issues with the OpenAPI support (since there are many gotchas and edge-cases when converting
|
||||
something as
|
||||
type-fluid as JSON to a strongly typed language), please open an issue on
|
||||
the [GitHub repo](https://github.com/Kotlin/dataframe/issues).
|
||||
@@ -0,0 +1,141 @@
|
||||
[//]: # (title: Import SQL Metadata as a Schema in Gradle Project)
|
||||
|
||||
<!---IMPORT org.jetbrains.kotlinx.dataframe.samples.api.Schemas-->
|
||||
|
||||
> The current Gradle plugin is **under consideration for deprecation** and may be officially marked as deprecated in future releases.
|
||||
>
|
||||
> At the moment, **[data schema generation is handled via dedicated methods](DataSchemaGenerationMethods.md)** instead of relying on the plugin.
|
||||
{style="warning"}
|
||||
|
||||
Each SQL database contains the metadata for all the tables.
|
||||
This metadata could be used for the schema generation.
|
||||
|
||||
**NOTE:** Visit this [page](readSqlDatabases.md) to see how to set up all Gradle dependencies for your project.
|
||||
|
||||
### With `@file:ImportDataSchema`
|
||||
|
||||
To generate schema for existing SQL table,
|
||||
you need to define a few parameters to establish JDBC connection:
|
||||
URL, username, and password.
|
||||
|
||||
Also, the `tableName` parameter could be specified.
|
||||
|
||||
You should also specify the name of the generated Kotlin class
|
||||
as the first parameter of the annotation `@file:ImportDataSchema`.
|
||||
|
||||
```kotlin
|
||||
@file:ImportDataSchema(
|
||||
"Directors",
|
||||
URL,
|
||||
jdbcOptions = JdbcOptions(USER_NAME, PASSWORD, tableName = TABLE_NAME_DIRECTORS)
|
||||
)
|
||||
|
||||
package org.jetbrains.kotlinx.dataframe.examples.jdbc
|
||||
|
||||
import org.jetbrains.kotlinx.dataframe.annotations.ImportDataSchema
|
||||
```
|
||||
|
||||
```kotlin
|
||||
const val URL = "jdbc:mariadb://localhost:3306/imdb"
|
||||
|
||||
const val USER_NAME = "root"
|
||||
|
||||
const val PASSWORD = "pass"
|
||||
|
||||
const val TABLE_NAME_DIRECTORS = "directors"
|
||||
```
|
||||
To generate schema for the result of an SQL query,
|
||||
you need to define the SQL query itself
|
||||
and the same parameters to establish connection with the database.
|
||||
|
||||
You should also specify the name of the generated Kotlin class
|
||||
as a first parameter of annotation `@file:ImportDataSchema`.
|
||||
|
||||
```kotlin
|
||||
@file:ImportDataSchema(
|
||||
"NewActors",
|
||||
URL,
|
||||
jdbcOptions = JdbcOptions(USER_NAME, PASSWORD, sqlQuery = ACTORS_IN_LATEST_MOVIES)
|
||||
)
|
||||
|
||||
package org.jetbrains.kotlinx.dataframe.examples.jdbc
|
||||
|
||||
import org.jetbrains.kotlinx.dataframe.annotations.ImportDataSchema
|
||||
```
|
||||
|
||||
```kotlin
|
||||
const val URL = "jdbc:mariadb://localhost:3306/imdb"
|
||||
|
||||
const val USER_NAME = "root"
|
||||
|
||||
const val PASSWORD = "pass"
|
||||
|
||||
const val ACTORS_IN_LATEST_MOVIES = """
|
||||
SELECT a.first_name, a.last_name, r.role, m.name AS movie_name, m.year
|
||||
FROM actors a
|
||||
INNER JOIN roles r ON a.id = r.actor_id
|
||||
INNER JOIN movies m ON m.id = r.movie_id
|
||||
WHERE m.year > 2000
|
||||
"""
|
||||
```
|
||||
|
||||
Find full example code [here](https://github.com/zaleslaw/KotlinDataFrame-SQL-Examples/blob/master/src/main/kotlin/Example_2_Import_schema_annotation.kt).
|
||||
|
||||
### With Gradle Task
|
||||
|
||||
To generate a schema for an existing SQL table,
|
||||
you need to define a few parameters to establish a JDBC connection:
|
||||
URL (passing to `data` field), username, and password.
|
||||
|
||||
Also, the `tableName` parameter should be specified to convert the data from the table with that name to the [`DataFrame`](DataFrame.md).
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
schema {
|
||||
data = "jdbc:mariadb://localhost:3306/imdb"
|
||||
name = "org.example.imdb.Actors"
|
||||
jdbcOptions {
|
||||
user = "root"
|
||||
password = "pass"
|
||||
tableName = "actors"
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
To generate a schema for the result of an SQL query,
|
||||
you need to define the same parameters as before together with the SQL query to establish connection.
|
||||
|
||||
|
||||
```kotlin
|
||||
dataframes {
|
||||
schema {
|
||||
data = "jdbc:mariadb://localhost:3306/imdb"
|
||||
name = "org.example.imdb.TarantinoFilms"
|
||||
jdbcOptions {
|
||||
user = "root"
|
||||
password = "pass"
|
||||
sqlQuery = """
|
||||
SELECT name, year, rank,
|
||||
GROUP_CONCAT (genre) as "genres"
|
||||
FROM movies JOIN movies_directors ON movie_id = movies.id
|
||||
JOIN directors ON directors.id=director_id LEFT JOIN movies_genres ON movies.id = movies_genres.movie_id
|
||||
WHERE directors.first_name = "Quentin" AND directors.last_name = "Tarantino"
|
||||
GROUP BY name, year, rank
|
||||
ORDER BY year
|
||||
"""
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Find full example code [here](https://github.com/zaleslaw/KotlinDataFrame-SQL-Examples/blob/master/src/main/kotlin/Example_3_Import_schema_via_Gradle.kt).
|
||||
|
||||
After importing the data schema, you can start to import any data from SQL table or as a result of an SQL query
|
||||
you like using the generated schemas.
|
||||
|
||||
Now you will have a correctly typed [`DataFrame`](DataFrame.md)!
|
||||
|
||||
If you experience any issues with the SQL databases support (since there are many edge-cases when converting
|
||||
SQL types from different databases to Kotlin types), please open an issue on
|
||||
the [GitHub repo](https://github.com/Kotlin/dataframe/issues), specifying the database and the problem.
|
||||
Reference in New Issue
Block a user