chore: Support text/varchar type in JDBC

Author: sakthivelmanii

src/main/java/com/google/cloud/spanner/jdbc/JdbcArray.java

@@ -60,9 +60,11 @@ class JdbcArray implements Array {
    *     the elements array is not compatible with the base type of the array.
    */
   static JdbcArray createArray(String typeName, Object[] elements) throws SQLException {
-    for (JdbcDataType type : JdbcDataType.values()) {
-      if (type.getTypeName().equalsIgnoreCase(typeName)) {
-        return new JdbcArray(type, elements);
+    if (typeName != null) {
+      for (JdbcDataType type : JdbcDataType.values()) {
+        if (type.matches(typeName)) {
+          return new JdbcArray(type, elements);
+        }
       }
     }
     throw JdbcSqlExceptionFactory.of(

src/main/java/com/google/cloud/spanner/jdbc/JdbcDataType.java

@@ -16,6 +16,7 @@
 
 package com.google.cloud.spanner.jdbc;
 
+import com.google.cloud.spanner.Dialect;
 import com.google.cloud.spanner.ResultSet;
 import com.google.cloud.spanner.Struct;
 import com.google.cloud.spanner.Type;
@@ -154,6 +155,7 @@ public Type getSpannerType() {
   },
   FLOAT64 {
     private final Set<Class<?>> classes = new HashSet<>(Arrays.asList(Float.class, Double.class));
+    private final Set<String> aliases = new HashSet<>(Collections.singletonList("float8"));
 
     @Override
     public int getSqlType() {
@@ -184,6 +186,11 @@ public List<Double> getArrayElements(ResultSet rs, int columnIndex) {
     public Type getSpannerType() {
       return Type.float64();
     }
+
+    @Override
+    public Set<String> getAliases() {
+      return aliases;
+    }
   },
   INT64 {
     private final Set<Class<?>> classes =
@@ -220,6 +227,9 @@ public Type getSpannerType() {
     }
   },
   NUMERIC {
+
+    private final Set<String> aliases = new HashSet<>(Collections.singletonList("decimal"));
+
     @Override
     public int getSqlType() {
       return Types.NUMERIC;
@@ -244,6 +254,11 @@ public List<BigDecimal> getArrayElements(ResultSet rs, int columnIndex) {
     public Type getSpannerType() {
       return Type.numeric();
     }
+
+    @Override
+    public Set<String> getAliases() {
+      return aliases;
+    }
   },
   PG_NUMERIC {
     @Override
@@ -272,6 +287,8 @@ public Type getSpannerType() {
     }
   },
   STRING {
+    private final Set<String> aliases = new HashSet<>(Arrays.asList("varchar", "text"));
+
     @Override
     public int getSqlType() {
       return Types.NVARCHAR;
@@ -296,6 +313,11 @@ public List<String> getArrayElements(ResultSet rs, int columnIndex) {
     public Type getSpannerType() {
       return Type.string();
     }
+
+    @Override
+    public Set<String> getAliases() {
+      return aliases;
+    }
   },
   JSON {
     @Override
@@ -498,6 +520,21 @@ public Type getSpannerType() {
 
   public abstract Type getSpannerType();
 
+  public Set<String> getAliases() {
+    return Collections.emptySet();
+  }
+
+  /***
+   * @param typeName type of the column
+   * @return true if type name matches current type name or matches with one of postgres aliases
+   * or if it matches equivalent postgres type.
+   */
+  public boolean matches(String typeName) {
+    return getTypeName().equalsIgnoreCase(typeName)
+        || getAliases().contains(typeName.toLowerCase())
+        || getSpannerType().getSpannerTypeName(Dialect.POSTGRESQL).equalsIgnoreCase(typeName);
+  }
+
   // TODO: Implement and use this method for all types.
   public int getPrecision() {
     throw new UnsupportedOperationException();

src/main/resources/com/google/cloud/spanner/jdbc/postgresql/DatabaseMetaData_GetColumns.sql

@@ -28,7 +28,20 @@ SELECT TABLE_CATALOG AS "TABLE_CAT", TABLE_SCHEMA AS "TABLE_SCHEM", TABLE_NAME A
            WHEN DATA_TYPE = 'jsonb' THEN -9
            WHEN DATA_TYPE = 'timestamp with time zone' THEN 93
            END AS "DATA_TYPE",
-       DATA_TYPE AS "TYPE_NAME",
+       CASE
+           WHEN DATA_TYPE LIKE 'ARRAY' THEN
+               CASE
+                   WHEN spanner_type LIKE '%[]' THEN
+                       CONCAT('_',
+                              REPLACE(
+                                      REPLACE(
+                                              REPLACE(spanner_type, '[]', ''),
+                                              'character varying', 'varchar'),
+                                      'boolean', 'bool'))
+                   ELSE spanner_type
+                   END
+           ELSE DATA_TYPE
+           END AS "TYPE_NAME",
        CASE
            WHEN DATA_TYPE LIKE 'ARRAY' THEN 0
            WHEN DATA_TYPE = 'boolean' THEN NULL