我正在尝试使用Apache Calcite查询Postgres数据库.我可以通过Calcite JDBC驱动程序仔细阅读有关数据库的元数据,因此我绝对能够连接到它,但每当我查询表时,Calcite总是以’table x not found’作为响应.如果我改变我的代码使用Hsqldb,一切正常.下面是代码(改编自此Calcite测试用例：
https://github.com/apache/calcite/blob/master/core/src/test/java/org/apache/calcite/test/MultiJdbcSchemaJoinTest.java)
package org.apache.calcite;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.sql.DataSource;
import org.apache.calcite.adapter.jdbc.JdbcSchema;
import org.apache.calcite.jdbc.CalciteConnection;
import org.apache.calcite.schema.SchemaPlus;
/**
* This class demonstrates Calcite unable to recognize tables in Postgres on
* Mac OS X 10.11.5 with Calcite 1.7.0, Postgres 9.5.2.0 and Java 1.8.0_77.
*
* Before you run this class, you must create the user and database in
* Postgres by executing the following SQL:
*
* create user johnsnow with password 'password';
* create database db1 with owner johnsnow;
*
*/
public class TableNotFoundMain {
public static void main(String... args) throws SQLException, ClassNotFoundException {
final String dbUrl = "jdbc:postgresql://localhost/db1";
Connection con = DriverManager.getConnection(dbUrl, "johnsnow", "password");
Statement stmt1 = con.createStatement();
stmt1.execute("drop table if exists table1");
stmt1.execute("create table table1(id varchar not null primary key, field1 varchar)");
stmt1.execute("insert into table1 values('a', 'aaaa')");
con.close();
Connection connection = DriverManager.getConnection("jdbc:calcite:");
CalciteConnection calciteConnection = connection.unwrap(CalciteConnection.class);
SchemaPlus rootSchema = calciteConnection.getRootSchema();
final DataSource ds = JdbcSchema.dataSource(dbUrl, "org.postgresql.Driver", "johnsnow", "password");
rootSchema.add("DB1", JdbcSchema.create(rootSchema, "DB1", ds, null, null));
Statement stmt3 = connection.createStatement();
ResultSet rs = stmt3.executeQuery("select * from db1.table1");
while (rs.next()) {
System.out.println(rs.getString(1) + '=' + rs.getString(2));
}
}
}
以下是我得到的错误：
Exception in thread "main" java.sql.SQLException: Error while executing SQL "select * from db1.table1": From line 1, column 15 to line 1, column 24: Table 'DB1.TABLE1' not found
at org.apache.calcite.avatica.Helper.createException(Helper.java:56)
at org.apache.calcite.avatica.Helper.createException(Helper.java:41)
at org.apache.calcite.avatica.AvaticaStatement.executeInternal(AvaticaStatement.java:143)
at org.apache.calcite.avatica.AvaticaStatement.executeQuery(AvaticaStatement.java:186)
at org.apache.calcite.TableNotFoundMain.main(TableNotFoundMain.java:45)
Caused by: org.apache.calcite.runtime.CalciteContextException: From line 1, column 15 to line 1, column 24: Table 'DB1.TABLE1' not found
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.calcite.runtime.Resources$ExInstWithCause.ex(Resources.java:405)
at org.apache.calcite.sql.SqlUtil.newContextException(SqlUtil.java:768)
at org.apache.calcite.sql.SqlUtil.newContextException(SqlUtil.java:753)
at org.apache.calcite.sql.validate.SqlValidatorImpl.newValidationError(SqlValidatorImpl.java:3929)
at org.apache.calcite.sql.validate.IdentifierNamespace.validateImpl(IdentifierNamespace.java:106)
at org.apache.calcite.sql.validate.AbstractNamespace.validate(AbstractNamespace.java:86)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateNamespace(SqlValidatorImpl.java:845)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateQuery(SqlValidatorImpl.java:831)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateFrom(SqlValidatorImpl.java:2754)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateFrom(SqlValidatorImpl.java:2739)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateSelect(SqlValidatorImpl.java:2957)
at org.apache.calcite.sql.validate.SelectNamespace.validateImpl(SelectNamespace.java:60)
at org.apache.calcite.sql.validate.AbstractNamespace.validate(AbstractNamespace.java:86)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateNamespace(SqlValidatorImpl.java:845)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateQuery(SqlValidatorImpl.java:831)
at org.apache.calcite.sql.SqlSelect.validate(SqlSelect.java:208)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validateScopedExpression(SqlValidatorImpl.java:807)
at org.apache.calcite.sql.validate.SqlValidatorImpl.validate(SqlValidatorImpl.java:523)
at org.apache.calcite.sql2rel.SqlToRelConverter.convertQuery(SqlToRelConverter.java:577)
at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:224)
at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:193)
at org.apache.calcite.prepare.CalcitePrepareImpl.prepare2_(CalcitePrepareImpl.java:720)
at org.apache.calcite.prepare.CalcitePrepareImpl.prepare_(CalcitePrepareImpl.java:587)
at org.apache.calcite.prepare.CalcitePrepareImpl.prepareSql(CalcitePrepareImpl.java:557)
at org.apache.calcite.jdbc.CalciteConnectionImpl.parseQuery(CalciteConnectionImpl.java:214)
at org.apache.calcite.jdbc.CalciteMetaImpl.prepareAndExecute(CalciteMetaImpl.java:573)
at org.apache.calcite.avatica.AvaticaConnection.prepareAndExecuteInternal(AvaticaConnection.java:581)
at org.apache.calcite.avatica.AvaticaStatement.executeInternal(AvaticaStatement.java:135)
... 2 more
Caused by: org.apache.calcite.sql.validate.SqlValidatorException: Table 'DB1.TABLE1' not found
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.calcite.runtime.Resources$ExInstWithCause.ex(Resources.java:405)
at org.apache.calcite.runtime.Resources$ExInst.ex(Resources.java:514)
... 29 more
我已经看到其他帖子(table not found with apache calcite)表明这些类型的错误通常是由套管问题引起的,所以我尝试了我能想到的每种套管组合：
ResultSet rs = stmt3.executeQuery("select * from DB1.TABLE1");
要么
ResultSet rs = stmt3.executeQuery("select * from \"DB1.table1\"");
要么
ResultSet rs = stmt3.executeQuery("select * from \"db1.table1\"");
但无济于事.
这是我的pom文件,因此您可以运行代码：
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.apache</groupId>
<artifactId>calcite-table-not-found</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.apache.calcite</groupId>
<artifactId>calcite-core</artifactId>
<version>1.7.0</version>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.4.1208.jre7</version>
</dependency>
</dependencies>
</project>
这里的最终用例是能够跨多个数据库进行查询.
最佳答案 这确实是一个套管问题,正确的语法如下：
ResultSet rs = stmt3.executeQuery("select * from db1.\"table1\"");
感谢Calcite项目团队成员Julian Hyde在Calcite dev邮件列表中提供答案.
