Merge pull request #71 from trocco-io/feature/match_by_column_name

support match_by_column_name

README.md

@@ -27,6 +27,7 @@ Snowflake output plugin for Embulk loads records to Snowflake.
 - **merge_keys**: key column names for merging records in merge mode (string array, required in merge mode if table doesn't have primary key)
 - **merge_rule**: list of column assignments for updating existing records used in merge mode, for example `"foo" = T."foo" + S."foo"` (`T` means target table and `S` means source table). (string array, default: always overwrites with new values)
 - **batch_size**: size of a single batch insert (integer, default: 16777216)
+- **match_by_column_name**: specify whether to load semi-structured data into columns in the target table that match corresponding columns represented in the data. ("case_sensitive", "case_insensitive", "none", default: "none")
 - **default_timezone**: If input column type (embulk type) is timestamp, this plugin needs to format the timestamp into a SQL string. This default_timezone option is used to control the timezone. You can overwrite timezone for each columns using column_options option. (string, default: `UTC`)
 - **column_options**: advanced: a key-value pairs where key is a column name and value is options for the column.
   - **type**: type of a column when this plugin creates new tables (e.g. `VARCHAR(255)`, `INTEGER NOT NULL UNIQUE`). This used when this plugin creates intermediate tables (insert, truncate_insert and merge modes), when it creates the target table (insert_direct and replace modes), and when it creates nonexistent target table automatically. (string, default: depends on input column type. `BIGINT` if input column type is long, `BOOLEAN` if boolean, `DOUBLE PRECISION` if double, `CLOB` if string, `TIMESTAMP` if timestamp)

src/main/java/org/embulk/output/SnowflakeOutputPlugin.java

@@ -1,9 +1,12 @@
 package org.embulk.output;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
 import java.io.IOException;
 import java.sql.SQLException;
 import java.sql.Types;
 import java.util.*;
+import java.util.function.BiFunction;
 import net.snowflake.client.jdbc.internal.org.bouncycastle.operator.OperatorCreationException;
 import net.snowflake.client.jdbc.internal.org.bouncycastle.pkcs.PKCSException;
 import org.embulk.config.ConfigDiff;
@@ -78,6 +81,47 @@ public interface SnowflakePluginTask extends PluginTask {
     @Config("delete_stage_on_error")
     @ConfigDefault("false")
     public boolean getDeleteStageOnError();
+
+    @Config("match_by_column_name")
+    @ConfigDefault("\"none\"")
+    public MatchByColumnName getMatchByColumnName();
+
+    public void setCopyIntoTableColumnNames(String[] columnNames);
+
+    public String[] getCopyIntoTableColumnNames();
+
+    public void setCopyIntoCSVColumnNumbers(int[] columnNumbers);
+
+    public int[] getCopyIntoCSVColumnNumbers();
+
+    public enum MatchByColumnName {
+      CASE_SENSITIVE,
+      CASE_INSENSITIVE,
+      NONE;
+
+      @JsonValue
+      @Override
+      public String toString() {
+        return name().toLowerCase(Locale.ENGLISH);
+      }
+
+      @JsonCreator
+      public static MatchByColumnName fromString(String value) {
+        switch (value) {
+          case "case_sensitive":
+            return CASE_SENSITIVE;
+          case "case_insensitive":
+            return CASE_INSENSITIVE;
+          case "none":
+            return NONE;
+          default:
+            throw new ConfigException(
+                String.format(
+                    "Unknown match_by_column_name '%s'. Supported values are case_sensitive, case_insensitive, none",
+                    value));
+        }
+      }
+    }
   }
 
   @Override
@@ -187,6 +231,38 @@ protected void doBegin(
       JdbcOutputConnection con, PluginTask task, final Schema schema, int taskCount)
       throws SQLException {
     super.doBegin(con, task, schema, taskCount);
+
+    SnowflakePluginTask pluginTask = (SnowflakePluginTask) task;
+    SnowflakePluginTask.MatchByColumnName matchByColumnName = pluginTask.getMatchByColumnName();
+    if (matchByColumnName == SnowflakePluginTask.MatchByColumnName.NONE) {
+      pluginTask.setCopyIntoCSVColumnNumbers(new int[0]);
+      pluginTask.setCopyIntoTableColumnNames(new String[0]);
+      return;
+    }
+
+    List<String> copyIntoTableColumnNames = new ArrayList<>();
+    List<Integer> copyIntoCSVColumnNumbers = new ArrayList<>();
+    JdbcSchema targetTableSchema = pluginTask.getTargetTableSchema();
+    BiFunction<String, String, Boolean> compare =
+        matchByColumnName == SnowflakePluginTask.MatchByColumnName.CASE_SENSITIVE
+            ? String::equals
+            : String::equalsIgnoreCase;
+    int columnNumber = 1;
+    for (int i = 0; i < targetTableSchema.getCount(); i++) {
+      JdbcColumn targetColumn = targetTableSchema.getColumn(i);
+      if (targetColumn.isSkipColumn()) {
+        continue;
+      }
+      Column schemaColumn = schema.getColumn(i);
+      if (compare.apply(schemaColumn.getName(), targetColumn.getName())) {
+        copyIntoTableColumnNames.add(targetColumn.getName());
+        copyIntoCSVColumnNumbers.add(columnNumber);
+      }
+      columnNumber += 1;
+    }
+    pluginTask.setCopyIntoTableColumnNames(copyIntoTableColumnNames.toArray(new String[0]));
+    pluginTask.setCopyIntoCSVColumnNumbers(
+        copyIntoCSVColumnNumbers.stream().mapToInt(i -> i).toArray());
   }
 
   @Override
@@ -201,6 +277,8 @@ protected BatchInsert newBatchInsert(PluginTask task, Optional<MergeConfig> merg
     return new SnowflakeCopyBatchInsert(
         getConnector(task, true),
         StageIdentifierHolder.getStageIdentifier(pluginTask),
+        pluginTask.getCopyIntoTableColumnNames(),
+        pluginTask.getCopyIntoCSVColumnNumbers(),
         false,
         pluginTask.getMaxUploadRetries(),
         pluginTask.getEmtpyFieldAsNull());

src/main/java/org/embulk/output/snowflake/SnowflakeCopyBatchInsert.java

@@ -40,9 +40,15 @@ public class SnowflakeCopyBatchInsert implements BatchInsert {
   private List<Future<Void>> uploadAndCopyFutures;
   private boolean emptyFieldAsNull;
 
+  private String[] copyIntoTableColumnNames;
+
+  private int[] copyIntoCSVColumnNumbers;
+
   public SnowflakeCopyBatchInsert(
       JdbcOutputConnector connector,
       StageIdentifier stageIdentifier,
+      String[] copyIntoTableColumnNames,
+      int[] copyIntoCSVColumnNumbers,
       boolean deleteStageFile,
       int maxUploadRetries,
       boolean emptyFieldAsNull)
@@ -51,6 +57,8 @@ public SnowflakeCopyBatchInsert(
     openNewFile();
     this.connector = connector;
     this.stageIdentifier = stageIdentifier;
+    this.copyIntoTableColumnNames = copyIntoTableColumnNames;
+    this.copyIntoCSVColumnNumbers = copyIntoCSVColumnNumbers;
     this.executorService = Executors.newCachedThreadPool();
     this.deleteStageFile = deleteStageFile;
     this.uploadAndCopyFutures = new ArrayList();
@@ -417,6 +425,8 @@ public Void call() throws SQLException, InterruptedException, ExecutionException
               tableIdentifier,
               stageIdentifier,
               snowflakeStageFileName,
+              copyIntoTableColumnNames,
+              copyIntoCSVColumnNumbers,
               delimiterString,
               emptyFieldAsNull);
 

src/main/java/org/embulk/output/snowflake/SnowflakeOutputConnection.java

@@ -25,11 +25,24 @@ public void runCopy(
       TableIdentifier tableIdentifier,
       StageIdentifier stageIdentifier,
       String filename,
+      String[] tableColumnNames,
+      int[] csvColumnNumbers,
       String delimiterString,
       boolean emptyFieldAsNull)
       throws SQLException {
     String sql =
-        buildCopySQL(tableIdentifier, stageIdentifier, filename, delimiterString, emptyFieldAsNull);
+        tableColumnNames != null && tableColumnNames.length > 0
+            ? buildCopySQL(
+                tableIdentifier,
+                stageIdentifier,
+                filename,
+                tableColumnNames,
+                csvColumnNumbers,
+                delimiterString,
+                emptyFieldAsNull)
+            : buildCopySQL(
+                tableIdentifier, stageIdentifier, filename, delimiterString, emptyFieldAsNull);
+
     runUpdate(sql);
   }
 
@@ -196,6 +209,50 @@ protected String buildCopySQL(
     return sb.toString();
   }
 
+  protected String buildCopySQL(
+      TableIdentifier tableIdentifier,
+      StageIdentifier stageIdentifier,
+      String snowflakeStageFileName,
+      String[] tableColumnNames,
+      int[] csvColumnNumbers,
+      String delimiterString,
+      boolean emptyFieldAsNull) {
+    // Data load with transformation
+    // Correspondence between CSV column numbers and table column names can be specified.
+    // https://docs.snowflake.com/ja/sql-reference/sql/copy-into-table
+
+    StringBuilder sb = new StringBuilder();
+    sb.append("COPY INTO ");
+    quoteTableIdentifier(sb, tableIdentifier);
+    sb.append(" (");
+    for (int i = 0; i < tableColumnNames.length; i++) {
+      if (i != 0) {
+        sb.append(", ");
+      }
+      String column = quoteIdentifierString(tableColumnNames[i]);
+      sb.append(column);
+    }
+    sb.append(" ) FROM ( SELECT ");
+    for (int i = 0; i < csvColumnNumbers.length; i++) {
+      if (i != 0) {
+        sb.append(", ");
+      }
+      sb.append("t.$");
+      sb.append(csvColumnNumbers[i]);
+    }
+    sb.append(" from ");
+    quoteInternalStoragePath(sb, stageIdentifier, snowflakeStageFileName);
+    sb.append(" t ) ");
+    sb.append(" FILE_FORMAT = ( TYPE = CSV FIELD_DELIMITER = '");
+    sb.append(delimiterString);
+    sb.append("'");
+    if (!emptyFieldAsNull) {
+      sb.append(" EMPTY_FIELD_AS_NULL = FALSE");
+    }
+    sb.append(" );");
+    return sb.toString();
+  }
+
   protected String buildDeleteStageFileSQL(
       StageIdentifier stageIdentifier, String snowflakeStageFileName) {
     StringBuilder sb = new StringBuilder();