feat: 新增last和first的column功能实现

hsweb-easy-orm-rdb/src/main/java/org/hswebframework/ezorm/rdb/supports/postgres/PostgresqlSchemaMetadata.java

@@ -28,6 +28,12 @@ public PostgresqlSchemaMetadata(String name) {
                 .add(FeatureUtils.r2dbcIsAlive(), () -> PostgresqlR2DBCExceptionTranslation.of(this))
         );
 
+        ValueByTimeFunctionFragmentBuilder last = new ValueByTimeFunctionFragmentBuilder("last", "最后一值");
+        ValueByTimeFunctionFragmentBuilder first = new ValueByTimeFunctionFragmentBuilder("first", "第一个值");
+
+        addFeature(last);
+        addFeature(first);
+
         addFeature((ValueCodecFactory) column -> {
             if(column.getType() instanceof ValueCodec){
                 return Optional.of(

hsweb-easy-orm-rdb/src/main/java/org/hswebframework/ezorm/rdb/supports/postgres/ValueByTimeFunctionFragmentBuilder.java

@@ -0,0 +1,79 @@
+package org.hswebframework.ezorm.rdb.supports.postgres;
+
+import com.google.common.collect.Lists;
+import lombok.Getter;
+import org.hswebframework.ezorm.rdb.metadata.RDBColumnMetadata;
+import org.hswebframework.ezorm.rdb.operator.builder.fragments.BatchSqlFragments;
+import org.hswebframework.ezorm.rdb.operator.builder.fragments.EmptySqlFragments;
+import org.hswebframework.ezorm.rdb.operator.builder.fragments.SqlFragments;
+import org.hswebframework.ezorm.rdb.operator.builder.fragments.function.FunctionFragmentBuilder;
+
+import java.sql.JDBCType;
+import java.sql.SQLType;
+import java.util.List;
+import java.util.Map;
+
+@Getter
+public class ValueByTimeFunctionFragmentBuilder implements FunctionFragmentBuilder {
+
+    //必须是 TIMESTAMP（时间戳）或 INTEGER（整数）类型 字段
+    public static final String TIME_COLUMN = "time";
+
+    private final String function;
+
+    private final String name;
+
+    private final SqlFragments FUNCTION;
+
+    private static final List<SQLType> timeTypes = Lists.newArrayList(JDBCType.TIMESTAMP, JDBCType.DATE, JDBCType.TIME,
+                                                                      JDBCType.TIME_WITH_TIMEZONE, JDBCType.TIMESTAMP_WITH_TIMEZONE);
+
+    public ValueByTimeFunctionFragmentBuilder(String function, String alias, String name) {
+        this.function = function;
+        this.name = name;
+        FUNCTION = SqlFragments.single(alias + "(");
+    }
+
+    public ValueByTimeFunctionFragmentBuilder(String function, String name) {
+        this.function = function;
+        this.name = name;
+        FUNCTION = SqlFragments.single(function + "(");
+    }
+
+
+    @Override
+    public SqlFragments create(String columnFullName, RDBColumnMetadata metadata, Map<String, Object> opts) {
+        String table = metadata.getOwner().getName();
+        String fullTimeColumn = null;
+        if (opts != null && opts.containsKey(TIME_COLUMN)) {
+            String timeColumn = (String) opts.get(TIME_COLUMN);
+            fullTimeColumn = metadata.getDialect().buildColumnFullName(table, timeColumn);
+        } else {
+            //优先获取时间类型字段、其次获取数字类型字段
+            RDBColumnMetadata numberBack = null;
+            for (RDBColumnMetadata column : metadata.getOwner().getColumns()) {
+                if (timeTypes.contains(column.getSqlType())) {
+                    fullTimeColumn = column.getFullName();
+                    break;
+                }
+                if (numberBack == null && column.getJavaType() != null && Number.class.isAssignableFrom(column.getJavaType())) {
+                    numberBack = column;
+                }
+            }
+            if (fullTimeColumn == null && numberBack != null) {
+                fullTimeColumn = numberBack.getFullName();
+            }
+        }
+        if (fullTimeColumn == null) {
+            throw new IllegalArgumentException("No time columns");
+        }
+        if (columnFullName == null) {
+            return EmptySqlFragments.INSTANCE;
+        }
+        return new BatchSqlFragments(2, 0)
+            .add(FUNCTION)
+            .addSql(columnFullName, ",", fullTimeColumn, ")");
+    }
+
+
+}

hsweb-easy-orm-rdb/src/test/java/org/hswebframework/ezorm/rdb/supports/postgres/ValueByTimeFunctionFragmentBuilderTest.java

@@ -0,0 +1,110 @@
+package org.hswebframework.ezorm.rdb.supports.postgres;
+
+import org.hswebframework.ezorm.rdb.metadata.JdbcDataType;
+import org.hswebframework.ezorm.rdb.metadata.RDBColumnMetadata;
+import org.hswebframework.ezorm.rdb.metadata.RDBDatabaseMetadata;
+import org.hswebframework.ezorm.rdb.metadata.RDBSchemaMetadata;
+import org.hswebframework.ezorm.rdb.metadata.RDBTableMetadata;
+import org.hswebframework.ezorm.rdb.metadata.dialect.Dialect;
+import org.hswebframework.ezorm.rdb.operator.builder.fragments.EmptySqlFragments;
+import org.hswebframework.ezorm.rdb.operator.builder.fragments.SqlFragments;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.sql.JDBCType;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Date;
+
+public class ValueByTimeFunctionFragmentBuilderTest {
+
+    @Test
+    public void shouldPreferDetectedTimeColumn() {
+        RDBTableMetadata table = createTable("metrics");
+        RDBColumnMetadata valueColumn = addColumn(table, "value", JDBCType.BIGINT, Long.class);
+        RDBColumnMetadata timeColumn = addColumn(table, "event_time", JDBCType.TIMESTAMP, Date.class);
+
+        ValueByTimeFunctionFragmentBuilder builder = new ValueByTimeFunctionFragmentBuilder("first", "第一个值");
+        SqlFragments fragments = builder.create(valueColumn.getFullName(), valueColumn, Collections.emptyMap());
+
+        Assert.assertEquals(
+            Arrays.asList(
+                "first(",
+                valueColumn.getFullName(),
+                ",",
+                timeColumn.getFullName(),
+                ")"
+            ),
+            fragments.getSql()
+        );
+    }
+
+    @Test
+    public void shouldFallbackToNumberColumnWhenNoTimeColumn() {
+        RDBTableMetadata table = createTable("metrics");
+        RDBColumnMetadata nameColumn = addColumn(table, "name", JDBCType.VARCHAR, String.class);
+        RDBColumnMetadata numberColumn = addColumn(table, "sequence", JDBCType.BIGINT, Long.class);
+
+        ValueByTimeFunctionFragmentBuilder builder = new ValueByTimeFunctionFragmentBuilder("last", "最后一值");
+        SqlFragments fragments = builder.create(nameColumn.getFullName(), nameColumn, Collections.emptyMap());
+
+        Assert.assertEquals(
+            Arrays.asList(
+                "last(",
+                nameColumn.getFullName(),
+                ",",
+                numberColumn.getFullName(),
+                ")"
+            ),
+            fragments.getSql()
+        );
+    }
+
+    @Test
+    public void shouldReturnEmptyFragmentsWhenColumnFullNameIsNull() {
+        RDBTableMetadata table = createTable("metrics");
+        RDBColumnMetadata valueColumn = addColumn(table, "value", JDBCType.DOUBLE, Double.class);
+        addColumn(table, "event_time", JDBCType.TIMESTAMP, Date.class);
+
+        ValueByTimeFunctionFragmentBuilder builder = new ValueByTimeFunctionFragmentBuilder("last", "最后一值");
+
+        Assert.assertSame(EmptySqlFragments.INSTANCE, builder.create(null, valueColumn, Collections.emptyMap()));
+    }
+
+    @Test
+    public void shouldThrowWhenNoTimeOrNumberColumnExists() {
+        RDBTableMetadata table = createTable("metrics");
+        RDBColumnMetadata textColumn = addColumn(table, "name", JDBCType.VARCHAR, String.class);
+
+        IllegalArgumentException error = Assert.assertThrows(
+            IllegalArgumentException.class,
+            () -> new ValueByTimeFunctionFragmentBuilder("last", "最后一值")
+                .create(textColumn.getFullName(), textColumn, Collections.emptyMap())
+        );
+
+        Assert.assertEquals("No time columns", error.getMessage());
+    }
+
+    private RDBTableMetadata createTable(String name) {
+        RDBSchemaMetadata schema = createSchema();
+        RDBTableMetadata table = schema.newTable(name);
+        schema.addTable(table);
+        return table;
+    }
+
+    private RDBSchemaMetadata createSchema() {
+        RDBDatabaseMetadata database = new RDBDatabaseMetadata(Dialect.POSTGRES);
+        RDBSchemaMetadata schema = new PostgresqlSchemaMetadata("public");
+        database.addSchema(schema);
+        database.setCurrentSchema(schema);
+        return schema;
+    }
+
+    private RDBColumnMetadata addColumn(RDBTableMetadata table, String name, JDBCType jdbcType, Class<?> javaType) {
+        RDBColumnMetadata column = table.newColumn();
+        column.setName(name);
+        column.setType(JdbcDataType.of(jdbcType, javaType));
+        table.addColumn(column);
+        return column;
+    }
+}