diff --git a/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegments.java b/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegments.java
index d34beb5..f5d905f 100755
--- a/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegments.java
+++ b/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegments.java
@@ -1,148 +1,148 @@
-package org.kpmp.geneExpression;
-
-import java.io.Serializable;
-
-import jakarta.persistence.Column;
-import jakarta.persistence.Entity;
-import jakarta.persistence.Id;
-import jakarta.persistence.Table;
-
-@Entity
-@Table(name = "rt_segments")
-public class RTExpressionDataAllSegments implements RTExpressionData, Serializable {
-
-	private static final long serialVersionUID = 9029734049386312455L;
-	@Id
-	@Column(name = "id")
-	private Integer id;
-	@Column(name = "gene_symbol")
-	private String geneSymbol;
-	@Column(name = "segment")
-	private String segment;
-	@Column(name = "segment_name")
-	private String segmentName;
-	@Column(name = "fold_change")
-	private Double foldChange;
-	@Column(name = "p_val")
-	private Double pVal;
-	@Column(name = "std_dev")
-	private Double stdDev;
-	@Column(name = "p_val_log10")
-	private Double pValLog10;
-	@Column(name = "enrollment_category")
-	private String enrollmentCategory;
-	@Column(name = "adj_p_val")
-	private Double adjPVal;
-	@Column(name = "sample_count")
-	private Integer sampleCount;
-
-	@Override
-	public Integer getId() {
-		return id;
-	}
-
-	@Override
-	public void setId(Integer id) {
-		this.id = id;
-	}
-
-	@Override
-	public String getGeneSymbol() {
-		return geneSymbol;
-	}
-
-	@Override
-	public void setGeneSymbol(String geneSymbol) {
-		this.geneSymbol = geneSymbol;
-	}
-
-	@Override
-	public String getSegment() {
-		return segment;
-	}
-
-	@Override
-	public void setSegment(String segment) {
-		this.segment = segment;
-	}
-
-	@Override
-	public Double getFoldChange() {
-		return foldChange;
-	}
-
-	@Override
-	public void setFoldChange(Double foldChange) {
-		this.foldChange = foldChange;
-	}
-
-	@Override
-	public Double getPVal() {
-		return pVal;
-	}
-
-	@Override
-	public void setPVal(Double pVal) {
-		this.pVal = pVal;
-	}
-
-	@Override
-	public Double getStdDev() {
-		return stdDev;
-	}
-
-	@Override
-	public void setStdDev(Double stdDev) {
-		this.stdDev = stdDev;
-	}
-
-	@Override
-	public Double getPValLog10() {
-		return pValLog10;
-	}
-
-	@Override
-	public void setPValLog10(Double pValLog10) {
-		this.pValLog10 = pValLog10;
-	}
-
-	@Override
-	public String getEnrollmentCategory() {
-		return enrollmentCategory;
-	}
-
-	@Override
-	public void setEnrollmentCategory(String enrollmentCategory) {
-		this.enrollmentCategory = enrollmentCategory;
-	}
-
-	@Override
-	public Integer getSampleCount() {
-		return sampleCount;
-	}
-
-	@Override
-	public void setSampleCount(Integer sampleCount) {
-		this.sampleCount = sampleCount;
-	}
-
-	@Override
-	public String getSegmentName() {
-		return segmentName;
-	}
-
-	@Override
-	public void setSegmentName(String segmentName) {
-		this.segmentName = segmentName;
-	}
-
-	@Override
-	public Double getAdjPVal() {
-		return adjPVal;
-	}
-
-	@Override
-	public void setAdjPVal(Double adjPVal) {
-		this.adjPVal = adjPVal;
-	}
-}
+package org.kpmp.geneExpression;
+
+import java.io.Serializable;
+
+import jakarta.persistence.*;
+
+@Entity
+@Table(name = "rt_segments")
+@IdClass(RTExpressionDataId.class)
+public class RTExpressionDataAllSegments implements RTExpressionData, Serializable {
+
+	private static final long serialVersionUID = 9029734049386312455L;
+	@Id
+	@Column(name = "id")
+	private Integer id;
+    @Id
+    @Column(name = "gene_symbol")
+	private String geneSymbol;
+	@Column(name = "segment")
+	private String segment;
+	@Column(name = "segment_name")
+	private String segmentName;
+	@Column(name = "fold_change")
+	private Double foldChange;
+    @Id
+	@Column(name = "p_val")
+	private Double pVal;
+	@Column(name = "std_dev")
+	private Double stdDev;
+	@Column(name = "p_val_log10")
+	private Double pValLog10;
+	@Column(name = "enrollment_category")
+	private String enrollmentCategory;
+	@Column(name = "adj_p_val")
+	private Double adjPVal;
+	@Column(name = "sample_count")
+	private Integer sampleCount;
+
+	@Override
+	public Integer getId() {
+		return id;
+	}
+
+	@Override
+	public void setId(Integer id) {
+		this.id = id;
+	}
+
+	@Override
+	public String getGeneSymbol() {
+		return geneSymbol;
+	}
+
+	@Override
+	public void setGeneSymbol(String geneSymbol) {
+		this.geneSymbol = geneSymbol;
+	}
+
+	@Override
+	public String getSegment() {
+		return segment;
+	}
+
+	@Override
+	public void setSegment(String segment) {
+		this.segment = segment;
+	}
+
+	@Override
+	public Double getFoldChange() {
+		return foldChange;
+	}
+
+	@Override
+	public void setFoldChange(Double foldChange) {
+		this.foldChange = foldChange;
+	}
+
+	@Override
+	public Double getPVal() {
+		return pVal;
+	}
+
+	@Override
+	public void setPVal(Double pVal) {
+		this.pVal = pVal;
+	}
+
+	@Override
+	public Double getStdDev() {
+		return stdDev;
+	}
+
+	@Override
+	public void setStdDev(Double stdDev) {
+		this.stdDev = stdDev;
+	}
+
+	@Override
+	public Double getPValLog10() {
+		return pValLog10;
+	}
+
+	@Override
+	public void setPValLog10(Double pValLog10) {
+		this.pValLog10 = pValLog10;
+	}
+
+	@Override
+	public String getEnrollmentCategory() {
+		return enrollmentCategory;
+	}
+
+	@Override
+	public void setEnrollmentCategory(String enrollmentCategory) {
+		this.enrollmentCategory = enrollmentCategory;
+	}
+
+	@Override
+	public Integer getSampleCount() {
+		return sampleCount;
+	}
+
+	@Override
+	public void setSampleCount(Integer sampleCount) {
+		this.sampleCount = sampleCount;
+	}
+
+	@Override
+	public String getSegmentName() {
+		return segmentName;
+	}
+
+	@Override
+	public void setSegmentName(String segmentName) {
+		this.segmentName = segmentName;
+	}
+
+	@Override
+	public Double getAdjPVal() {
+		return adjPVal;
+	}
+
+	@Override
+	public void setAdjPVal(Double adjPVal) {
+		this.adjPVal = adjPVal;
+	}
+}
diff --git a/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegmentsRepository.java b/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegmentsRepository.java
index 7227691..79a5d5e 100755
--- a/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegmentsRepository.java
+++ b/src/main/java/org/kpmp/geneExpression/RTExpressionDataAllSegmentsRepository.java
@@ -9,7 +9,7 @@
 import org.springframework.stereotype.Repository;
 
 @Repository
-public interface RTExpressionDataAllSegmentsRepository extends CrudRepository<RTExpressionDataAllSegments, Integer> {
+public interface RTExpressionDataAllSegmentsRepository extends CrudRepository<RTExpressionDataAllSegments, RTExpressionDataId> {
 	@Cacheable("rtExpGeneSymbolAndEnrollmentCategoryWithCounts")
 	@Query(value = "SELECT rts.*, rsv.sample_count, s.segment_name FROM rt_segments rts "
 			+ "LEFT JOIN rt_summary_v rsv ON rts.segment = rsv.segment AND rts.enrollment_category = rsv.enrollment_category "
diff --git a/src/main/java/org/kpmp/geneExpression/RTExpressionDataId.java b/src/main/java/org/kpmp/geneExpression/RTExpressionDataId.java
new file mode 100644
index 0000000..88c78d2
--- /dev/null
+++ b/src/main/java/org/kpmp/geneExpression/RTExpressionDataId.java
@@ -0,0 +1,39 @@
+package org.kpmp.geneExpression;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+public class RTExpressionDataId implements Serializable {
+
+    private Integer id;
+    private String geneSymbol;
+    private Double pVal;
+
+    public RTExpressionDataId() {}
+
+    public RTExpressionDataId(Integer id, String geneSymbol, Double pVal) {
+        this.id = id;
+        this.geneSymbol = geneSymbol;
+        this.pVal = pVal;
+    }
+
+    public Integer getId() { return id; }
+    public void setId(Integer id) { this.id = id; }
+    public String getGeneSymbol() { return geneSymbol; }
+    public void setGeneSymbol(String geneSymbol) { this.geneSymbol = geneSymbol; }
+    public Double getPVal() { return pVal; }
+    public void setPVal(Double pVal) { this.pVal = pVal; }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        RTExpressionDataId that = (RTExpressionDataId) o;
+        return Objects.equals(id, that.id) && Objects.equals(geneSymbol, that.geneSymbol) && Objects.equals(pVal, that.pVal);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, geneSymbol, pVal);
+    }
+}
diff --git a/src/test/java/org/kpmp/geneExpression/RTExpressionDataIdTest.java b/src/test/java/org/kpmp/geneExpression/RTExpressionDataIdTest.java
new file mode 100644
index 0000000..876c325
--- /dev/null
+++ b/src/test/java/org/kpmp/geneExpression/RTExpressionDataIdTest.java
@@ -0,0 +1,46 @@
+package org.kpmp.geneExpression;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import org.junit.jupiter.api.Test;
+
+class RTExpressionDataIdTest {
+
+    @Test
+    void testGettersAndSetters() {
+        RTExpressionDataId idData = new RTExpressionDataId();
+
+        idData.setId(101);
+        idData.setGeneSymbol("SOD1");
+        idData.setPVal(0.05);
+
+        assertEquals(101, idData.getId());
+        assertEquals("SOD1", idData.getGeneSymbol());
+        assertEquals(0.05, idData.getPVal());
+    }
+
+    @Test
+    void testConstructor() {
+        RTExpressionDataId idData = new RTExpressionDataId(202, "GAPDH", 0.001);
+
+        assertEquals(202, idData.getId());
+        assertEquals("GAPDH", idData.getGeneSymbol());
+        assertEquals(0.001, idData.getPVal());
+    }
+
+    @Test
+    void testEqualsAndHashCode() {
+        RTExpressionDataId id1 = new RTExpressionDataId(1, "ALB", 0.01);
+        RTExpressionDataId id2 = new RTExpressionDataId(1, "ALB", 0.01);
+        RTExpressionDataId id3 = new RTExpressionDataId(2, "ALB", 0.01);
+        RTExpressionDataId id4 = new RTExpressionDataId(1, "INS", 0.01);
+
+        assertEquals(id1, id2);
+        assertNotEquals(id1, id3);
+        assertNotEquals(id1, id4);
+        assertNotEquals(null, id1);
+
+        assertEquals(id1.hashCode(), id2.hashCode());
+        assertNotEquals(id1.hashCode(), id3.hashCode());
+    }
+}