用Python写一个连接postgis的代码
时间: 2023-03-15 18:56:38 浏览: 94
使用Python来连接Postgis,首先,你需要安装psycopg2库,然后使用以下代码:
import psycopg2
conn = psycopg2.connect(dbname="yourdatabasename", user="youruser", password="yourpassword", host="localhost", port="5432")
cur = conn.cursor()
cur.execute("SELECT * FROM yourtable")
rows = cur.fetchall()
for row in rows:
print(row)
conn.close()
相关问题
我在用flink 版 sedona ,连接postgis 和oracle 转 postgis 代码怎么写
以下是连接PostGIS和Oracle转PostGIS的示例代码:
```scala
import org.apache.flink.streaming.api.scala._
import org.apache.flink.api.scala._
import org.apache.sedona.core.enums.{FileDataSplitter, GridType}
import org.apache.sedona.core.formatMapper.shapefileParser.ShapefileReader
import org.apache.sedona.core.spatialRDD.LineStringRDD
import org.apache.sedona.core.spatialOperator.JoinQuery
import org.apache.sedona.viz.core.Serde.SedonaVizKryoRegistrator
import org.apache.spark.serializer.KryoSerializer
import org.apache.spark.serializer.KryoSerializerInstance
import org.datasyslab.geospark.enums.{FileDataSplitter, GridType}
import org.datasyslab.geospark.formatMapper.shapefileParser.ShapefileReader
import org.datasyslab.geospark.spatialRDD.LineStringRDD
import org.datasyslab.geospark.spatialOperator.JoinQuery
import org.datasyslab.geosparkviz.core.Serde.SedonaVizKryoRegistrator
import org.datasyslab.geosparkviz.extension.visualizationEffect.{ChoroplethMap, ScatterPlot}
import org.datasyslab.geosparkviz.sql.utils.{Adapter, GeoSparkVizRegistrator}
import org.datasyslab.geosparkviz.utils.{ColorizeOption, ImageType}
import org.datasyslab.geosparkviz.{MapConfig, RendererType}
import org.apache.spark.sql.SparkSession
import org.apache.spark.sql.types.{DataTypes, StructField, StructType}
import org.geotools.data.{DataStoreFinder, Query}
import org.geotools.jdbc.JDBCDataStore
import org.opengis.feature.simple.{SimpleFeature, SimpleFeatureType}
import org.opengis.filter.Filter
object SedonaPostGISOracle {
def main(args: Array[String]): Unit = {
val sparkSession = SparkSession.builder()
.master("local[*]")
.appName("SedonaPostGISOracle")
.config("spark.serializer", classOf[KryoSerializer].getName)
.config("spark.kryo.registrator", classOf[SedonaVizKryoRegistrator].getName)
.config("spark.kryoserializer.buffer.max", "512m")
.config("spark.driver.maxResultSize", "4g")
.getOrCreate()
GeoSparkVizRegistrator.registerAll(sparkSession)
val postGISConnectionProperties = new java.util.HashMap[String, String]()
postGISConnectionProperties.put("user", "postgres")
postGISConnectionProperties.put("password", "postgres")
postGISConnectionProperties.put("driver", "org.postgresql.Driver")
postGISConnectionProperties.put("url", "jdbc:postgresql://localhost:5432/postgis")
val oracleConnectionProperties = new java.util.HashMap[String, String]()
oracleConnectionProperties.put("user", "oracle")
oracleConnectionProperties.put("password", "oracle")
oracleConnectionProperties.put("driver", "oracle.jdbc.driver.OracleDriver")
oracleConnectionProperties.put("url", "jdbc:oracle:thin:@localhost:1521:ORCL")
oracleConnectionProperties.put("dbtable", "LINESTRINGTABLE")
val postGISQuery = "(select st_astext(geom) as wkt from public.linestringtable) as linestringtable"
val postGISLineStringDF = sparkSession.read.jdbc(postGISConnectionProperties.get("url"), postGISQuery, postGISConnectionProperties)
postGISLineStringDF.createOrReplaceTempView("postGISLineStringTable")
val oracleLineStringDF = sparkSession.read.jdbc(oracleConnectionProperties.get("url"), oracleConnectionProperties.get("dbtable"), oracleConnectionProperties)
oracleLineStringDF.createOrReplaceTempView("oracleLineStringTable")
val postGISLineStringRDD = ShapefileReader.readToLineStringRDD(postGISLineStringDF.rdd, true, true)
val oracleLineStringRDD = ShapefileReader.readToLineStringRDD(oracleLineStringDF.rdd, true, true)
val joinResultPairRDD = JoinQuery.SpatialJoinQueryFlat(postGISLineStringRDD, oracleLineStringRDD, false, false)
val joinResultDf = Adapter.toDf(joinResultPairRDD, sparkSession)
joinResultDf.show()
sparkSession.stop()
}
}
```
需要注意的是,需要将代码中的连接信息替换为你自己的连接信息。
python 链接postgis
Python链接PostGIS是将Python编程语言与PostgreSQL的关系数据库管理系统(尤其是其扩展模块PostGIS,用于处理地理空间数据)结合起来的过程。PostGIS提供了丰富的SQL功能来操作和分析地理数据,而Python作为强大的通用编程语言,可以方便地与PostGIS进行交互。
使用Python连接PostGIS的步骤通常包括:
1. **安装必要库**:首先确保已安装Python和psycopg2或geopandas等用于连接PostgreSQL的库。`psycopg2`是标准的Python PostgreSQL适配器,而`geopandas`则提供了更高级的数据处理和可视化接口。
```bash
pip install psycopg2-binary
# 或者,如果需要更高级的地理空间处理能力
pip install geopandas
```
2. **连接数据库**:使用`psycopg2.connect()`函数创建到PostGIS数据库的连接,提供数据库地址、用户名、密码等信息。
```python
import psycopg2
conn = psycopg2.connect(
dbname="your_database_name",
user="your_username",
password="your_password",
host="localhost",
port=5432 # PostGIS默认端口
)
```
3. **执行SQL查询**:在连接建立后,可以使用`conn.cursor()`创建游标并执行SQL命令,如查询地理数据。
```python
cursor = conn.cursor()
cursor.execute("SELECT * FROM your_table")
results = cursor.fetchall()
```
4. **处理返回结果**:根据查询结果执行数据处理、分析或可视化操作。
5. **关闭连接**:完成操作后,记得关闭连接释放资源。
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