72 lines
2.0 KiB
Markdown
Vendored
72 lines
2.0 KiB
Markdown
Vendored
# PostgreSQL
|
||
|
||
<web-summary>
|
||
Work with PostgreSQL databases in Kotlin — read tables and queries into DataFrames using JDBC.
|
||
</web-summary>
|
||
|
||
<card-summary>
|
||
Use Kotlin DataFrame to query and transform PostgreSQL data directly via JDBC.
|
||
</card-summary>
|
||
|
||
<link-summary>
|
||
Read PostgreSQL data into Kotlin DataFrame with JDBC support.
|
||
</link-summary>
|
||
|
||
|
||
Kotlin DataFrame supports reading from [PostgreSQL](https://www.postgresql.org) database using JDBC.
|
||
|
||
Requires the [`dataframe-jdbc` module](Modules.md#dataframe-jdbc),
|
||
which is included by default in the general [`dataframe` artifact](Modules.md#dataframe-general)
|
||
and in [`%use dataframe`](SetupKotlinNotebook.md#integrate-kotlin-dataframe) for Kotlin Notebook.
|
||
|
||
You’ll also need [the official PostgreSQL JDBC driver](https://jdbc.postgresql.org):
|
||
|
||
<tabs>
|
||
<tab title="Gradle project">
|
||
|
||
```kotlin
|
||
dependencies {
|
||
implementation("org.postgresql:postgresql:$version")
|
||
}
|
||
```
|
||
|
||
</tab>
|
||
<tab title="Kotlin Notebook">
|
||
|
||
|
||
```kotlin
|
||
USE {
|
||
dependencies("org.postgresql:postgresql:$version")
|
||
}
|
||
```
|
||
|
||
</tab>
|
||
</tabs>
|
||
|
||
The actual Maven Central driver version could be found
|
||
[here](https://mvnrepository.com/artifact/org.postgresql/postgresql).
|
||
|
||
## Read
|
||
|
||
[`DataFrame`](DataFrame.md) can be loaded from a database in several ways:
|
||
a user can read data from a SQL table by given name ([`readSqlTable`](readSqlDatabases.md)),
|
||
as a result of a user-defined SQL query ([`readSqlQuery`](readSqlDatabases.md)),
|
||
or from a given `ResultSet` ([`readResultSet`](readSqlDatabases.md)).
|
||
It is also possible to load all data from non-system tables, each into a separate `DataFrame` ([`readAllSqlTables`](readSqlDatabases.md)).
|
||
|
||
See [](readSqlDatabases.md) for more details.
|
||
|
||
```kotlin
|
||
import org.jetbrains.kotlinx.dataframe.io.DbConnectionConfig
|
||
|
||
val url = "jdbc:postgresql://localhost:5432/testDatabase"
|
||
val username = "postgres"
|
||
val password = "password"
|
||
|
||
val dbConfig = DbConnectionConfig(url, username, password)
|
||
|
||
val tableName = "Customer"
|
||
|
||
val df = DataFrame.readSqlTable(dbConfig, tableName)
|
||
```
|