diff --git a/pegjs/postgresql.pegjs b/pegjs/postgresql.pegjs
index f1d8ba7d..342f31d3 100644
--- a/pegjs/postgresql.pegjs
+++ b/pegjs/postgresql.pegjs
@@ -817,7 +817,7 @@ create_table_stmt
           type: a[0].toLowerCase(),
           keyword: 'table',
           temporary: tp && tp[0].toLowerCase(),
-          if_not_exists:ife,
+          if_not_exists: ife,
           table: t,
           partition_of: po
         }
@@ -1672,12 +1672,17 @@ alter_schema_stmt
 alter_table_stmt
   = KW_ALTER  __
     KW_TABLE __
+    ife:if_exists? __
+    o:'only'i? __
     t:table_ref_list __
     e:alter_action_list {
       /*
       export interface alter_table_stmt_node {
         type: 'alter';
         table: table_ref_list;
+        keyword: 'table';
+        if_exists: if_exists;
+        prefix?: literal_string;
         expr: alter_action_list;
       }
       => AstStatement<alter_table_stmt_node>
@@ -1688,6 +1693,9 @@ alter_table_stmt
         columnList: columnListTableAlias(columnList),
         ast: {
           type: 'alter',
+          keyword: 'table',
+          if_exists: ife,
+          prefix: o && { type: 'origin', value: o },
           table: t,
           expr: e
         }
@@ -1709,21 +1717,27 @@ alter_action
   / ALTER_RENAME
   / ALTER_ALGORITHM
   / ALTER_LOCK
+  / ALTER_COLUMN_DATA_TYPE
+  / ALTER_COLUMN_DEFAULT
+  / ALTER_COLUMN_NOT_NULL
 
 ALTER_ADD_COLUMN
   = KW_ADD __
     kc:KW_COLUMN? __
+    ife:if_not_exists_stmt? __
     cd:create_column_definition {
       /*
       => {
         action: 'add';
         keyword: KW_COLUMN;
         resource: 'column';
+        if_not_exists: ife;
         type: 'alter';
       } & create_column_definition;
       */
       return {
         action: 'add',
+        if_not_exists: ife,
         ...cd,
         keyword: kc,
         resource: 'column',
@@ -1734,17 +1748,20 @@ ALTER_ADD_COLUMN
 ALTER_DROP_COLUMN
   = KW_DROP __
     kc:KW_COLUMN? __
+    ife:if_exists? __
     c:column_ref {
       /* => {
         action: 'drop';
         collumn: column_ref;
         keyword: KW_COLUMN;
+        if_exists: if_exists;
         resource: 'column';
         type: 'alter';
       } */
       return {
         action: 'drop',
         column: c,
+        if_exists: ife,
         keyword: kc,
         resource: 'column',
         type: 'alter',
@@ -1863,6 +1880,89 @@ ALTER_LOCK
     }
   }
 
+ALTER_COLUMN_DATA_TYPE
+  = KW_ALTER __ kc:KW_COLUMN? __ c:column_ref __ sd:(KW_SET __ 'data'i)? __ 'type'i __ t:data_type __ co:collate_expr? __ us:(KW_USING __ expr)? {
+    /*
+      => {
+        action: 'alter';
+        keyword?: KW_COLUMN;
+        using?: expr;
+        type: 'alter';
+      } & create_column_definition;
+      */
+      c.suffix = sd ? 'set data type' : 'type'
+      return {
+        action: 'alter',
+        column: c,
+        keyword: kc,
+        resource: 'column',
+        definition: t,
+        collate: co,
+        using: us && us[2],
+        type: 'alter',
+      }
+  }
+
+ALTER_COLUMN_DEFAULT
+  = KW_ALTER __ kc:KW_COLUMN? __ c:column_ref __ KW_SET __ KW_DEFAULT __ e:expr {
+    /* => {
+        action: 'alter';
+        keyword?: KW_COLUMN;
+        default_val?: { type: 'set default', value: expr };
+        type: 'alter';
+      } & create_column_definition;
+      */
+      return {
+        action: 'alter',
+        column: c,
+        keyword: kc,
+        resource: 'column',
+        default_val: {
+          type: 'set default',
+          value: e,
+        },
+        type: 'alter',
+      }
+  }
+  / KW_ALTER __ kc:KW_COLUMN? __ c:column_ref __ KW_DROP __ KW_DEFAULT {
+    /* => {
+        action: 'alter';
+        keyword?: KW_COLUMN;
+        default_val?: { type: 'set default', value: expr };
+        type: 'alter';
+      } & create_column_definition;
+      */
+      return {
+        action: 'alter',
+        column: c,
+        keyword: kc,
+        resource: 'column',
+        default_val: {
+          type: 'drop default',
+        },
+        type: 'alter',
+      }
+  }
+
+ALTER_COLUMN_NOT_NULL
+  = KW_ALTER __ kc:KW_COLUMN? __ c:column_ref __ ac:(KW_SET / KW_DROP) __ n:literal_not_null {
+    /* => {
+        action: 'alter';
+        keyword?: KW_COLUMN;
+        nullable: literal_not_null;
+        type: 'alter';
+      } & create_column_definition;
+      */
+      n.action = ac.toLowerCase();
+      return {
+        action: 'alter',
+        column: c,
+        keyword: kc,
+        resource: 'column',
+        nullable: n,
+        type: 'alter',
+      }
+  }
 create_index_definition
   = kc:(KW_INDEX / KW_KEY) __
     c:column? __
diff --git a/src/alter.js b/src/alter.js
index b607b7ce..79ec14a3 100644
--- a/src/alter.js
+++ b/src/alter.js
@@ -4,14 +4,15 @@ import { indexTypeAndOptionToSQL } from './index-definition'
 import { tablesToSQL, tableToSQL } from './tables'
 import { exprToSQL } from './expr'
 import { selectToSQL } from './select'
-import { dataTypeToSQL, hasVal, toUpper, identifierToSql } from './util'
+import { dataTypeToSQL, hasVal, toUpper, identifierToSql, literalToSQL } from './util'
 
 function alterExprToSQL(expr) {
   if (!expr) return ''
   const {
     action,
     create_definitions: createDefinition,
-    if_not_exists: ifNotExists,keyword,
+    if_not_exists: ifNotExists, keyword,
+    if_exists: ifExists,
     old_column: oldColumn,
     prefix,
     resource,
@@ -58,6 +59,7 @@ function alterExprToSQL(expr) {
     toUpper(action),
     toUpper(keyword),
     toUpper(ifNotExists),
+    toUpper(ifExists),
     oldColumn && columnRefToSQL(oldColumn),
     toUpper(prefix),
     name && name.trim(),
@@ -68,11 +70,11 @@ function alterExprToSQL(expr) {
 }
 
 function alterTableToSQL(stmt) {
-  const { type, table, expr = [] } = stmt
+  const { type, table, if_exists, prefix, expr = [] } = stmt
   const action = toUpper(type)
   const tableName = tablesToSQL(table)
   const exprList = expr.map(exprToSQL)
-  const result = [action, 'TABLE', tableName, exprList.join(', ')]
+  const result = [action, 'TABLE', toUpper(if_exists), literalToSQL(prefix), tableName, exprList.join(', ')]
   return result.filter(hasVal).join(' ')
 }
 
diff --git a/src/column.js b/src/column.js
index 5012655c..2b2b0d2a 100644
--- a/src/column.js
+++ b/src/column.js
@@ -96,7 +96,7 @@ function columnReferenceDefinitionToSQL(referenceDefinition) {
 function columnOption(definition) {
   const columnOpt = []
   const {
-    nullable, character_set: characterSet, check, comment, collate, storage,
+    nullable, character_set: characterSet, check, comment, collate, storage, using,
     default_val: defaultOpt,
     auto_increment: autoIncrement,
     unique: uniqueKey,
@@ -105,7 +105,7 @@ function columnOption(definition) {
     reference_definition: referenceDefinition,
   } = definition
 
-  columnOpt.push(toUpper(nullable && nullable.value))
+  columnOpt.push(toUpper(nullable && nullable.action), toUpper(nullable && nullable.value))
   if (defaultOpt) {
     const { type, value } = defaultOpt
     columnOpt.push(type.toUpperCase(), exprToSQL(value))
@@ -118,6 +118,7 @@ function columnOption(definition) {
   columnOpt.push(...commonTypeValue(columnFormat))
   columnOpt.push(...commonTypeValue(storage))
   columnOpt.push(...columnReferenceDefinitionToSQL(referenceDefinition))
+  columnOpt.push(commonOptionConnector('USING', exprToSQL, using))
   return columnOpt.filter(hasVal).join(' ')
 }
 
diff --git a/test/postgres.spec.js b/test/postgres.spec.js
index 9fd00c45..23d9761e 100644
--- a/test/postgres.spec.js
+++ b/test/postgres.spec.js
@@ -865,8 +865,8 @@ describe('Postgres', () => {
     {
       title: 'alter table add constraint',
       sql: [
-        'ALTER TABLE address ADD CONSTRAINT user_id_address_fk FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE ON UPDATE RESTRICT;',
-        'ALTER TABLE "address" ADD CONSTRAINT "user_id_address_fk" FOREIGN KEY (user_id) REFERENCES "user" (id) ON DELETE CASCADE ON UPDATE RESTRICT'
+        'ALTER TABLE if exists only address ADD CONSTRAINT user_id_address_fk FOREIGN KEY (user_id) REFERENCES user (id) ON DELETE CASCADE ON UPDATE RESTRICT;',
+        'ALTER TABLE IF EXISTS ONLY "address" ADD CONSTRAINT "user_id_address_fk" FOREIGN KEY (user_id) REFERENCES "user" (id) ON DELETE CASCADE ON UPDATE RESTRICT'
       ]
     },
     {
@@ -1540,7 +1540,28 @@ describe('Postgres', () => {
      LIMIT 1;`,
      `SELECT somefunc("engineering_networks".realizaciya, "engineering_networks".company = 'blah-blah' AND "engineering_networks".obem_realizacii_tip = 'uslugi') AS "var0", If(var0 > 0, '2', '1') AS "fontColor" FROM "engineering_networks" AS "engineering_networks" WHERE "engineering_networks".company = 'blah-blah' AND "engineering_networks".month IN ('April') AND "engineering_networks".year IN ('2024') LIMIT 1`
       ],
-    }
+    },
+    {
+      title: 'alter column data type',
+      sql: [
+        `ALTER TABLE employees ALTER COLUMN first_name SET DATA TYPE TEXT COLLATE "C" using upper(first_name);`,
+        'ALTER TABLE "employees" ALTER COLUMN first_name SET DATA TYPE TEXT COLLATE "C" USING upper(first_name)'
+      ]
+    },
+    {
+      title: 'alter column set and drop default',
+      sql: [
+        "ALTER TABLE transactions ADD COLUMN status varchar(30) DEFAULT 'old', ALTER COLUMN status SET default 'current', ALTER COLUMN name drop default;",
+        `ALTER TABLE "transactions" ADD COLUMN status VARCHAR(30) DEFAULT 'old', ALTER COLUMN status SET DEFAULT 'current', ALTER COLUMN name DROP DEFAULT`,
+      ]
+    },
+    {
+      title: 'alter column set not null',
+      sql: [
+        'ALTER TABLE transactions ALTER COLUMN status SET NOT NULL',
+        'ALTER TABLE "transactions" ALTER COLUMN status SET NOT NULL',
+      ]
+    },
   ]
   function neatlyNestTestedSQL(sqlList){
     sqlList.forEach(sqlInfo => {